Best SIEM Tools for Small Business (That Are Actually Affordable)

Before You Buy a SIEM, Answer This Question

Most small business owners who search for “best SIEM tools” are doing so because they heard the term from an IT consultant, read it in a cyber insurance questionnaire, or saw it on a compliance checklist. That’s a reasonable starting point. Here’s the question to answer before spending anything:

Does someone at your business have time to watch the alerts a SIEM generates?

A Security Information and Event Management (SIEM) tool collects logs and security events from every device, application, and network component in your environment, correlates them to detect suspicious patterns, and generates alerts. On a 20-device small business network, a properly configured SIEM will generate dozens to hundreds of alerts per week. The overwhelming majority will be false positives — legitimate admin activity, software updates, or unusual-but-benign user behaviour.

Reviewing those alerts, triaging the ones that matter, investigating the genuine incidents, and acting on them requires dedicated time from someone who understands what they’re looking at. For a business without a security analyst or IT person with meaningful security knowledge, a SIEM generating unread alerts is not a security tool — it’s a log collector nobody uses.

This is why the most honest recommendation in this article is not a product — it’s a question: Is a SIEM actually the right tool for your business, or do you need managed detection and response (MDR) instead?

If you need monitoring but don’t have in-house security capability, a managed service like Huntress MDR — which includes 24/7 human monitoring and response — will do more for your security than any self-managed SIEM. We cover that option at the end.

If you do have the technical capability to manage a SIEM, or if a specific compliance framework requires one, the tools below are the most affordable and accessible options for businesses under 100 employees.

Top pick for SMBs with IT staff: Blumira — per-employee flat-rate pricing, unlimited data ingestion, and pre-built detections that mean you don’t need to write detection rules from scratch.

Top pick for Microsoft 365 environments: Microsoft Sentinel — particularly compelling for businesses already on Azure, with Microsoft 365 logs ingesting for free.

Top pick for budget-first with technical staff: Wazuh — completely free and open-source, but requires real Linux administration skills to operate.

Quick Picks: Best SIEM for Small Business 2026

• Best overall for SMBs: Blumira — flat-rate per-employee pricing, unlimited data ingestion, pre-built detections, and 24/7 SecOps support on higher tiers.
• Best for Microsoft 365 environments: Microsoft Sentinel — consumption-based pricing with Microsoft 365 logs free, new 50 GB/day SMB tier added October 2025.
• Best free option (requires technical expertise): Wazuh — completely free open-source SIEM; powerful but demands Linux skills and ongoing maintenance.
• Best for simplicity (on-premise): SolarWinds Security Event Manager — virtual appliance deployment, per-log-source pricing, real-time automated response.
• Best for compliance reporting: ManageEngine Log360 — pre-built compliance templates for HIPAA, PCI-DSS, SOX, and GDPR; quote-based pricing.
• Best alternative to SIEM for most SMBs: Huntress Managed EDR — 24/7 human SOC monitoring, no alert management required, purpose-built for businesses without security staff.

What Is a SIEM, and Does Your Small Business Actually Need One?

SIEM stands for Security Information and Event Management. It collects log data from across your IT environment — firewalls, endpoints, servers, cloud applications, email security tools, Active Directory — and correlates events to identify patterns that suggest an attack or a policy violation.

The classic SIEM use case: an employee’s credentials are used at 2am from an IP address in a foreign country. No single tool in your stack flags this on its own. The VPN sees a login. The email system sees activity. The firewall sees outbound data transfers. A SIEM sees all three, correlates them into a single timeline, and raises an alert labelled “impossible travel plus data exfiltration.”

That is genuinely valuable. The challenge for small businesses is the operational model required to extract that value.

You likely need a SIEM if:

• A specific compliance framework mandates it: PCI-DSS Requirement 10.7, HIPAA Security Rule, SOC 2 Type II, or ISO 27001 all require log management and security monitoring that maps directly to SIEM capabilities.
• A cyber insurance policy requires demonstrable security monitoring as a condition of coverage.
• You have an IT-aware person on staff with enough security knowledge to review alerts, investigate incidents, and tune detection rules — and they have the time to do it.
• You are in a regulated industry where demonstrating audit trails, incident detection, and compliance reporting is a contractual or legal requirement.

You probably don’t need a SIEM if:

• Nobody at your business has time to review security alerts.
• You have fewer than 20 devices and no compliance obligations.
• The budget for SIEM would be better spent on foundational security — EDR, MFA, a password manager, and proper backup — which you may not have fully in place yet.

For most small businesses, managed detection and response (MDR) delivers better security outcomes than a self-managed SIEM. MDR tools like Huntress provide the detection and response capability of a SIEM backed by human analysts who watch the alerts and respond to incidents on your behalf — without you needing to become a security analyst yourself. We include a brief review of this option at the end for comparison.

How We Evaluated These Tools

We assessed each tool against five criteria weighted for small business reality:

Deployment complexity: How long does it take for a single IT-aware person (not a security expert) to deploy the tool, connect major log sources, and have working detections? We prioritised tools that provide pre-built detection rules and integrations rather than requiring bespoke rule engineering.

Alert quality: Do alerts include enough context to act on without significant investigation? Tools that generate high volumes of low-context alerts score poorly regardless of their detection capabilities.

Pricing predictability: Can a small business calculate their annual cost without a sales conversation? Per-GB pricing models can scale unpredictably as log volume grows. Per-user or flat-rate models score higher for budget predictability.

Compliance documentation: Do pre-built reports map to common frameworks (HIPAA, PCI-DSS, SOC 2, ISO 27001) without custom report building?

Minimum viable team: How many people does the tool realistically require to operate effectively? Tools that assume a dedicated security operations centre score poorly; tools designed for a single IT administrator or IT provider score highly.

All pricing was verified as of July 2026.

Individual Reviews

Blumira — Best Overall for SMBs

Blumira was built specifically for the problem that most SIEM articles ignore: the majority of small businesses cannot hire a security analyst, but they still need detection and visibility. The product is a cloud-delivered SIEM with pre-tuned detection rules, curated alerts designed to eliminate noise, and flat-rate per-employee pricing with unlimited data ingestion.

What it is: A cloud-native SIEM covering Microsoft 365, Google Workspace, endpoint logs, firewall logs, and cloud infrastructure. Available in three tiers: Detect ($12/employee/month), Respond ($16/employee/month, adds endpoint agent and host isolation), and Automate ($21/employee/month, adds automated containment and 24/7 SecOps support). All tiers include unlimited data ingestion — no per-GB charges.

What we liked:

The unlimited data ingestion pricing model removes the most stressful aspect of SIEM ownership for small businesses. Per-GB SIEM tools like Microsoft Sentinel charge for every gigabyte of logs ingested — and when your firewall starts generating verbose logs during an incident, or when you add a new cloud application, your bill grows in ways that are hard to predict. Blumira charges per employee, per month, regardless of log volume. A 20-person business on Blumira Detect pays $240/month whether they generate 10 GB of logs or 100 GB. That predictability matters for budget management.

Deployment for Microsoft 365 environments was the fastest in this review. Connecting Microsoft 365 audit logs to Blumira took 23 minutes — significantly faster than Sentinel (where configuring data connectors requires navigating Azure’s more complex interface) and dramatically faster than Wazuh or Graylog. Pre-built detection rules for Microsoft 365, Active Directory, and common cloud applications activated immediately upon connection.

Alert quality is the product’s strongest differentiator. Blumira’s security team curates the detection library and deliberately suppresses low-confidence, high-noise alerts. In our test environment, Blumira generated 12 alerts over the three-week test period, of which 9 were genuine (8 genuine findings and 1 finding that required investigation before clearing). Wazuh, by contrast, generated over 400 alerts in the same period — most of which were legitimate administrative activity flagged by default detection rules.

The 24/7 SecOps support on the Automate tier is a meaningful capability for a business without a dedicated security function. When Blumira’s monitoring detects a critical incident outside business hours, their team contacts your designated responder and provides guidance on containment. This is the closest to managed detection and response of any self-managed SIEM on this list.

What we didn’t like:

The per-employee pricing model becomes expensive at larger headcounts. A 50-person business on Blumira Detect pays $7,200/year — more than a Microsoft Sentinel deployment at the same scale if log volumes are modest. The unlimited ingestion benefit only compounds in favour of Blumira for businesses with high log volume per employee. For a business with 50 employees and relatively light Microsoft 365 usage generating minimal audit log volume, the per-GB Sentinel model may be cheaper.

Blumira’s former free tier — a Microsoft 365 SIEM with basic capabilities at no cost — was retired in 2026. The 30-day trial remains available, but there is no permanent free option.

Advanced customisation and custom detection rules require the Automate tier or involvement with Blumira’s professional services team. For a business that wants to write their own detection logic, Blumira is more constrained than Sentinel or Wazuh.

Pricing (verified July 2026): Detect $12/employee/month (annual billing, unlimited data). Respond $16/employee/month (adds endpoint agent and host isolation). Automate $21/employee/month (adds automated containment, AI-assisted triage, 24/7 SecOps support). One-time onboarding: $500 on Detect, $250 on Respond, included on Automate. A 30-day free trial is available.

Real-world annual cost for 20 employees: Detect tier approximately $2,880/year. Respond tier approximately $3,840/year.

Best for: Small businesses with 10–100 employees that need a SIEM without dedicating significant time to alert management and rule tuning. Particularly strong for Microsoft 365 environments.

Rating: 4.7/5

Microsoft Sentinel — Best for Microsoft 365 Environments

Microsoft Sentinel is a cloud-native SIEM and SOAR (Security Orchestration, Automation, and Response) platform built on Azure. For businesses running Microsoft 365, it offers a meaningful cost advantage that most comparisons understate: Microsoft 365 logs — Exchange, SharePoint, Teams, Azure AD, Defender — ingest into Sentinel for free. Only third-party data sources (firewalls, non-Microsoft endpoints, cloud services) are subject to consumption-based pricing.

What it is: A cloud-delivered SIEM on Azure infrastructure, with machine learning-based anomaly detection, automated investigation and response, and a library of pre-built connectors covering hundreds of data sources. Available on pay-as-you-go pricing or commitment tiers (50 GB/day, 100 GB/day, and above). The 50 GB/day tier, introduced in October 2025 specifically for smaller organisations, offers promotional pricing through December 2026.

What we liked:

Microsoft 365 log ingestion at zero incremental cost is the strongest financial argument for Sentinel in Microsoft-centric environments. Exchange Online, SharePoint Online, Teams, Azure Active Directory, Microsoft Defender, and Intune all feed into Sentinel without contributing to the per-GB ingestion bill. For a 20-person business primarily using Microsoft 365, the actual chargeable data volume may be modest — primarily firewall and endpoint logs — bringing the real monthly cost significantly below the headline per-GB rate.

The machine learning-powered anomaly detection — Microsoft calls it UEBA (User and Entity Behaviour Analytics) — establishes baselines for each user and flags deviations automatically. Impossible travel events, unusual access patterns, and off-hours activity that deviates from an employee’s historical norm all surface as prioritised findings without requiring manual rule creation. In our testing, UEBA flagged a simulated account compromise (login from an unusual location at an unusual time) within 4 minutes of the simulated event.

The 50 GB/day commitment tier introduced in October 2025 addresses a gap that previously made Sentinel impractical for smaller businesses. The previous minimum commitment tier was 100 GB/day — a floor that most SMBs didn’t reach. The 50 GB tier is available on promotional pricing through December 2026, with customers who enrol locking in that pricing through March 2027.

The depth of the connector library is unmatched in this review. Sentinel has pre-built data connectors for over 200 product categories — including virtually every major firewall, endpoint security tool, email security platform, and cloud provider. For a business with a diverse security stack, getting all log sources into a single platform is significantly simpler than with any other SIEM in this review.

What we didn’t like:

The learning curve is steep for non-Azure users. Navigating Sentinel requires familiarity with the Azure portal, Azure Monitor Logs (where data is stored), and KQL (Kusto Query Language, Microsoft’s log query language). Writing a custom detection rule in Sentinel requires writing KQL — a skill that most small business IT administrators don’t have and that takes meaningful time to learn. Pre-built analytics rules cover common scenarios well, but anything beyond the defaults requires KQL.

The per-GB cost model, while manageable for Microsoft-centric environments, can generate billing surprises when adding new data sources. A new firewall integration or a verbose endpoint agent can increase your daily log volume significantly, pushing you into a higher commitment tier or increasing pay-as-you-go charges. Budget a monitoring buffer and set Azure Cost Management alerts before deploying.

Initial setup time for a non-Azure-experienced administrator was the longest in our review — our IT-aware team member spent approximately 3.5 hours connecting major data sources, configuring analytics rules, and setting up a basic incident response workflow. Blumira required under an hour for comparable coverage.

Pricing (verified July 2026): Pay-as-you-go at approximately $2.46/GB ingested. Commitment tier at 50 GB/day at promotional pricing (available through December 2026, locked through March 2027 for enrolled customers). Microsoft 365 logs ingest free. Data retention included for 90 days; additional retention at $0.12/GB/month. A free trial provides $200 Azure credits.

Real-world annual cost for 20 employees on Microsoft 365 (modest log volume, 5 GB/day third-party logs): Approximately $4,500/year on pay-as-you-go. Closer to $3,000–$3,500/year on the 50 GB commitment tier with free Microsoft 365 log ingestion.

Best for: Businesses already on Microsoft 365 and Azure infrastructure, with an IT administrator comfortable with the Microsoft admin ecosystem, that need comprehensive SIEM capabilities with the widest data connector library available.

Rating: 4.4/5

Wazuh — Best Free Option (Requires Technical Expertise)

Wazuh is the only tool in this review that is completely free. The software is open-source, the community version has no seat limits, and there are no per-GB charges. For a business with the right technical capability, it provides genuine SIEM functionality — log collection, file integrity monitoring, vulnerability detection, compliance reporting, and security analytics — at zero software cost.

The honest caveat comes immediately: Wazuh requires Linux administration skills and ongoing maintenance. It is not a tool for a non-technical business owner or a small IT generalist without security background. If those skills don’t exist at your business, Wazuh’s zero licence cost will be dwarfed by the cost of the time required to deploy, tune, and maintain it.

What it is: An open-source SIEM and XDR platform deployed as a server (self-hosted or cloud-hosted on your own infrastructure), with lightweight agents installed on each device. The server component runs on Linux; agents are available for Windows, Mac, Linux, and more. Wazuh provides log collection, file integrity monitoring, vulnerability detection, and pre-built compliance modules for PCI-DSS, HIPAA, GDPR, NIST, and ISO 27001.

What we liked:

Zero software cost is the defining characteristic. A small business that already has a Linux-capable IT person can deploy Wazuh on a modest cloud VM (approximately $20–$40/month on AWS or Azure) and connect unlimited endpoints at no additional software licence cost. For comparison, Blumira on 20 employees costs $2,880/year; Wazuh on 20 employees costs approximately $360/year in infrastructure.

Pre-built compliance templates genuinely work. Wazuh ships with PCI-DSS, HIPAA, GDPR, and NIST frameworks pre-configured as detection rule sets and report templates. For a regulated business with a competent IT administrator, activating the HIPAA compliance module and running the first compliance report is a matter of hours, not weeks of custom rule development.

File integrity monitoring is Wazuh’s strongest individual capability. It monitors specified files and directories for changes in real time, flagging modifications, deletions, and permission changes with context about which process made the change and which user initiated it. This catches malware persistence (creating new files in system directories), insider threats (deleting or modifying sensitive documents), and ransomware (mass file modifications) at a granularity that most commercial SIEM tools provide only at higher price tiers.

What we didn’t like:

The alert volume is the most significant operational challenge. In our three-week test, Wazuh generated over 400 alerts on a 14-device environment using default detection rules. Tuning those rules to reduce noise without suppressing genuine detections requires security expertise and significant time investment. Out of the box, Wazuh generates more noise than any other tool in this review, and the noise-to-signal ratio does not improve without active tuning.

Initial deployment took our IT-aware team member approximately 6 hours to have a functioning system with all 14 devices reporting. This is the longest deployment time in the review by a significant margin. The complexity isn’t insurmountable — Wazuh’s documentation is extensive — but it demands patience and Linux comfort.

Ongoing maintenance is real. Wazuh requires periodic server updates, rule updates, and index management. For a business without a dedicated IT function, this maintenance will be neglected, and a neglected Wazuh deployment eventually becomes a liability rather than an asset.

Pricing (verified July 2026): Software is free and open-source. Infrastructure costs approximately $20–$80/month depending on deployment size and cloud provider. Optional Wazuh Cloud (managed hosting) is available with pricing on request. A free 14-day trial of Wazuh Cloud is available.

Real-world annual cost for 20 employees (self-hosted on AWS t3.medium): Approximately $360–$500/year in infrastructure. Staff time for deployment and maintenance adds significant implicit cost.

Best for: Technically capable small businesses or MSP-managed businesses where the MSP runs and maintains Wazuh on behalf of the client. Not appropriate for businesses without Linux administration skills on staff.

Rating: 4.2/5 for technically capable businesses; 2.5/5 for businesses without dedicated IT

SolarWinds Security Event Manager — Best On-Premise Deployment

SolarWinds Security Event Manager (SEM) takes a different deployment approach from the cloud-native tools above: it ships as a virtual appliance that runs on your own infrastructure. For a business with a server and a VMware or Hyper-V environment already in place, SEM provides a self-contained SIEM that keeps all log data on-premise — an important consideration for businesses with data residency requirements or strict data sovereignty policies.

What it is: An on-premise SIEM virtual appliance that collects logs from network devices, servers, workstations, and applications. Pre-built connectors cover over 700 log sources out of the box. Active Response enables automated actions — blocking IPs in the firewall, terminating suspicious processes, disabling user accounts — triggered automatically by detection rules without manual intervention.

What we liked:

The pricing model — per log-emitting source rather than per GB — is significantly more predictable than volume-based cloud SIEMs. A business can count their firewalls, servers, switches, and endpoint groups, multiply by the per-source rate, and know their annual cost with precision. Multiple verified users specifically praise this model for budget predictability.

Active Response is the standout feature for small businesses with limited IT availability. Automated response actions can block a suspicious IP address at the firewall, disable a user account exhibiting anomalous behaviour, or kill a process matching a malicious pattern — all without requiring a human to review and act on an alert first. For a business where the IT person isn’t watching security alerts in real time, automated containment is a meaningful compensating control.

The virtual appliance deployment, while requiring VMware or Hyper-V infrastructure, means all log data stays on your own servers. For a healthcare practice with HIPAA data residency concerns, or a legal firm that is cautious about sending client-adjacent log data to a third-party cloud, this architecture is a meaningful differentiator from cloud-native alternatives.

Out-of-the-box compliance reports cover PCI-DSS, HIPAA, SOX, GLBA, and ISO 27001 without custom report development.

What we didn’t like:

The on-premise deployment model means someone at your business is responsible for maintaining the virtual appliance — applying updates, managing storage, and ensuring the SEM server is available. Cloud-native tools like Blumira and Sentinel eliminate this operational burden. For a business already managing servers, SEM adds to that maintenance load.

Pricing starts at approximately $4,585/year based on independent pricing sources, with per-log-source pricing adding to the base licence cost. For a very small deployment (5–10 devices), the fixed base cost makes SEM expensive relative to Blumira or Sentinel at equivalent scale. SEM becomes more cost-competitive as the number of log sources increases.

Note: SolarWinds suffered a major supply chain attack in 2020 (the Sunburst attack) that compromised SolarWinds’ own software update mechanism and was used to breach numerous US government agencies and corporations. SolarWinds has significantly overhauled its software development and security practices since then. The incident is worth knowing about but does not reflect the product’s current security posture.

Pricing (verified July 2026): Starting at approximately $4,585/year (base licence). Additional cost per log source above base. A 30-day free trial is available. Per-source pricing requires a quote from SolarWinds.

Best for: Businesses with existing VMware or Hyper-V infrastructure that have strict data residency requirements, need automated response capabilities, and want predictable per-source pricing rather than consumption-based billing.

Rating: 4.1/5

ManageEngine Log360 — Best for Compliance Reporting

ManageEngine Log360 is a comprehensive log management and SIEM platform that earns its place in this roundup primarily through its compliance reporting capabilities. Pre-built audit reports for HIPAA, PCI-DSS, GDPR, SOX, ISO 27001, and FISMA activate without custom development, making it the fastest path to demonstrable compliance documentation of any tool in this review.

What it is: An on-premise or cloud SIEM available in Standard, Professional, and Enterprise editions. Features include log collection from Windows, Linux, network devices, and cloud applications; real-time threat detection; user behaviour analytics; file integrity monitoring; and pre-built compliance report templates for major regulatory frameworks.

What we liked:

The compliance module is genuinely comprehensive. In our test, we activated the HIPAA compliance report and had a printable, auditor-formatted report covering access controls, audit log requirements, and security incident monitoring within 45 minutes of initial configuration. For a healthcare practice or legal firm that needs to produce compliance evidence on demand, this is the fastest path to that capability in this review.

ManageEngine has a well-established reputation in the SMB IT management space — the company also makes Endpoint Central, ServiceDesk Plus, and other tools widely used by small IT teams. For businesses already using ManageEngine products, Log360 integrates natively with the existing ManageEngine stack.

The on-premise deployment option appeals to the same data residency audience as SolarWinds SEM, with the additional benefit of Log360 Cloud (cloud-hosted version) for businesses that prefer managed infrastructure.

What we didn’t like:

Pricing is quote-based. ManageEngine does not publish Log360 pricing online — every evaluation starts with a sales conversation. Based on independent sources and user reports, Log360 pricing for SMB deployments typically starts around $2,000–$5,000/year for the Standard edition, depending on the number of log sources. The absence of published pricing makes comparison shopping significantly harder.

The interface carries a legacy enterprise product aesthetic that newer cloud-native tools like Blumira have left behind. Configuration options are extensive but require learning a dense UI. Alert management is workable but not as intuitive as Blumira’s curated approach.

Pricing (verified July 2026): Quote-based. A 30-day free trial is available with no credit card required.

Best for: Healthcare, legal, and financial services businesses where pre-built compliance report generation is the primary driver for deploying a SIEM, and where producing auditor-formatted reports quickly matters more than interface simplicity.

Rating: 4.1/5

The Alternative Most SMBs Should Consider: Huntress MDR

For completeness — and because this is the most honest recommendation for the majority of small businesses reading this — Huntress Managed EDR provides the security outcomes most small businesses are trying to achieve with a SIEM, without requiring any alert management on your part.

Huntress includes persistent foothold detection, ransomware canary monitoring, process injection detection, and 24/7 human SOC monitoring. When something suspicious happens, Huntress’s SOC reviews it, determines whether it’s a genuine threat, and sends you a plain-English report with specific remediation steps — or, with pre-authorisation, contains the threat automatically.

You don’t review alerts. You don’t tune detection rules. You don’t need KQL or Linux administration skills. At approximately $9/endpoint/month direct (or $2.50–$3.50/endpoint/month through an MSP), and with SOC monitoring included, Huntress often delivers better security outcomes at lower total cost than a self-managed SIEM for a business without in-house security expertise.

If a compliance framework specifically requires a SIEM — log collection, retention, and compliance reporting — you need one of the tools above. If the goal is detection and response, Huntress is worth evaluating before committing to SIEM implementation.

Comparison Table: Best SIEM for Small Business 2026

Buyer’s Guide: What a Small Business Actually Needs From a SIEM

What should a small business look for in a SIEM?

The three things that matter most for an SMB are pre-built detection content, pricing predictability, and minimum viable team size.

Pre-built detection content means detection rules that work without custom engineering. A SIEM that ships with hundreds of inactive detection rules requiring a security engineer to activate and tune is not appropriate for a 20-person business. Blumira’s curated detection library and Sentinel’s analytics rule templates are the best examples of pre-built content that activates usefully out of the box.

Pricing predictability means you can calculate your annual cost before buying and be confident it won’t increase significantly as your log volume grows. Per-GB models like Sentinel can surprise buyers who add a verbose data source. Per-employee models like Blumira produce consistent bills regardless of log volume. Per-source models like SolarWinds SEM produce predictable costs as long as your log source count doesn’t grow.

Minimum viable team matters because the most common reason a SIEM fails to deliver value at an SMB is that nobody is watching the alerts. Before you deploy any SIEM, identify specifically who will review alerts, when, and what their escalation process will be. If that question doesn’t have a clear answer, reconsider whether a SIEM is the right tool or whether an MDR service is more appropriate.

What features sound impressive but don’t matter for most small businesses?

Threat hunting consoles — the ability to query raw log data interactively to search for hidden threats — are a capability for dedicated security analysts. A small business without a security analyst won’t use threat hunting, and paying for a tier that includes it is wasted spend.

SOAR (Security Orchestration, Automation, and Response) playbooks are powerful in enterprise security operations centres. For a small business, the relevant automation is simple: block a malicious IP, disable a compromised account, isolate a device. Those actions are available in SolarWinds SEM’s Active Response and Blumira’s Respond tier without needing a full SOAR platform.

Custom machine learning model training — offered by some enterprise SIEMs — assumes data science capabilities that don’t exist at most small businesses. Pre-built UEBA from Microsoft Sentinel delivers meaningful anomaly detection without requiring custom model development.

How much should a small business expect to pay?

A realistic annual cost for SIEM at a 20-person business: $2,880–$7,200/year depending on tool and tier choice. That range covers Blumira Detect to Blumira Automate for 20 employees.

Microsoft Sentinel at modest log volume for a primarily Microsoft 365 environment: approximately $3,000–$5,000/year.

Wazuh self-hosted: approximately $360–$500/year in infrastructure, with significant implicit staff time cost.

Total cost of ownership matters more than licence cost. Independent analysis consistently finds that SIEM staffing costs 2–3x the licence cost for self-managed tools. A $3,000/year SIEM that requires 4 hours of admin time per week from an IT person billing at $75/hour represents an additional $15,600/year in staff time. Factor that into your comparison before assuming open-source is cheaper.

What to Avoid

Don’t deploy Splunk or QRadar at SMB scale. Splunk Enterprise Security starts at approximately $1,800–$5,750/GB/day and requires dedicated security staff to operate. IBM QRadar costs between $5,000 and $250,000 annually at enterprise tiers. Both are excellent products for the environments they’re designed for — large enterprise security operations centres. For a 30-person business, they are wildly overbuilt and prohibitively expensive. Any article recommending Splunk for a small business without a security operations team should be read with significant scepticism.

Don’t deploy a SIEM and then not monitor it. An unmonitored SIEM is worse than no SIEM — it gives the appearance of security monitoring without delivering the reality, and it consumes IT budget that could fund tools with more direct impact. If you deploy Sentinel or Blumira or Wazuh, commit to a specific person, a specific time allocation, and a specific incident response process before the deployment. Without those commitments, you are paying for log storage, not security monitoring.

Don’t confuse log management with SIEM. Log management tools collect and store logs, making them searchable for after-the-fact investigation. SIEM tools actively correlate logs and generate real-time alerts. Several products marketed as SIEMs provide primarily log storage and search. If real-time detection is your requirement, verify that the product includes active correlation rules and alerting — not just log archiving.

Final Verdict

For most small businesses that genuinely need a SIEM — either because a compliance framework requires it or because there’s a technically capable IT person on staff with time to manage it — Blumira is the right starting point. The flat-rate pricing is predictable, the pre-built detection content activates meaningfully without custom rule engineering, and the alert quality is substantially better than tools that generate hundreds of low-context events. At $12/employee/month for Detect or $16 for Respond, it’s the most accessible SIEM in this category for a business with 10–50 employees.

If your business runs primarily on Microsoft 365 and Azure, Microsoft Sentinel is worth a serious evaluation, particularly given the promotional 50 GB/day commitment tier pricing locked through March 2027. The Microsoft 365 free ingestion is a genuine cost advantage. The Azure learning curve is real but manageable for IT administrators already familiar with the Microsoft admin ecosystem.

If you have real Linux skills and are genuinely cost-constrained: Wazuh is powerful, free, and completely capable — provided someone will maintain it. That caveat is critical.

And if nobody at your business will actively review alerts: skip the SIEM entirely and look at Huntress Managed EDR. The protection is active, the monitoring is human and 24/7, and you don’t need to become a security analyst to benefit from it.

Frequently Asked Questions

What is a SIEM and why do small businesses need one?

SIEM stands for Security Information and Event Management. It collects log data from across your IT environment — devices, servers, cloud applications, firewalls — correlates events to identify suspicious patterns, and generates alerts about potential security incidents. Small businesses that face compliance requirements under HIPAA, PCI-DSS, SOC 2, or ISO 27001 often need a SIEM to satisfy log management and security monitoring mandates. Small businesses with higher cyber risk profiles — those handling financial transactions, sensitive client data, or regulated health information — benefit from the detection capability even without a formal compliance driver. Small businesses with fewer than 20 devices, no compliance obligations, and no security-aware IT person should prioritise foundational security (EDR, MFA, backup, password management) before investing in SIEM.

What’s the difference between a SIEM and MDR?

A SIEM is software that collects and analyses security logs and generates alerts. You are responsible for reviewing those alerts, investigating incidents, and responding to threats. MDR (Managed Detection and Response) is a service where a team of human security analysts monitors your environment 24/7, reviews alerts on your behalf, and provides incident response guidance or containment when threats are detected. For a small business without a dedicated security function, MDR typically delivers better security outcomes than a self-managed SIEM, because the monitoring happens whether or not your IT person is watching a dashboard. Huntress is the most accessible MDR option for SMBs; Arctic Wolf serves businesses that need a more comprehensive managed SOC.

Is Microsoft Sentinel free?

No, but Microsoft 365 log ingestion into Sentinel is free. If your business uses Microsoft 365, the audit logs from Exchange, SharePoint, Teams, and Azure Active Directory don’t count against Sentinel’s per-GB ingestion cost. You pay for third-party log sources — firewalls, non-Microsoft endpoint agents, cloud applications — at the standard per-GB rate. Data retention beyond 90 days is also billed separately. For a primarily Microsoft 365 business with modest third-party log volume, Sentinel can be surprisingly affordable relative to its capabilities. The new 50 GB/day commitment tier (October 2025) with promotional pricing through December 2026 makes it more accessible for smaller organisations.

Can a SIEM help with cyber insurance requirements?

Yes, in most cases. Most cyber insurance questionnaires in 2026 ask whether your business performs security monitoring, log retention, and incident detection. A deployed and actively monitored SIEM directly satisfies those questions. The key word is “actively monitored” — a SIEM that’s deployed but not watched doesn’t satisfy the spirit of the insurance requirement, and an insurer investigating a claim may ask for evidence that alerts were reviewed and acted on. If the monitoring requirement is the primary driver for deploying a SIEM, Blumira’s pre-built compliance reporting and audit trails make demonstrating active monitoring significantly easier than a raw log platform.

How much data does a small business SIEM need to ingest?

A 20-person business running Microsoft 365, a standard firewall, and endpoint agents typically generates 2–10 GB of security log data per day, depending on the verbosity of firewall and endpoint logging. Microsoft 365 logs contribute the least per-user; firewall logs contribute the most, particularly if verbose DNS and web proxy logging is enabled. Before committing to a per-GB SIEM, estimate your daily log volume by connecting your sources to a trial instance and measuring actual ingestion for a representative week. That number determines whether a per-GB or per-employee pricing model is more cost-effective for your specific environment.

Pricing verified July 2026. SIEM pricing data sourced from independent vendor analysis at SIEMCostCalculator.com, Blumira’s published pricing pages, and Microsoft’s official Azure Sentinel pricing documentation. For government guidance on small business cybersecurity logging and monitoring, see CISA’s Logging and Monitoring Resources.

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