The best SIEM tool depends on your team: an open source SIEM suits technical teams with time to tune it, a managed platform suits small IT teams without a SOC, and an enterprise SIEM suits large security operations centres. Ten options follow in no particular order.
A SIEM, or security information and event management tool, collects logs from your systems and looks for signs of trouble: odd logins, unusual data movement, malware alerts. It's the place your team looks first when something might be wrong.
The ten SIEM tools below are listed alphabetically and in no particular order, from open source platforms to suites run by large security teams. Every description comes from the vendor's own site, read this week. If you're new to the threats a SIEM watches for, my explainer on what ransomware is and how it works is a useful primer.
SIEM tools at a glance
In the free plan column, Yes means the tool's own site names a free plan, a free tier, a free portal or an open source edition. Trial only means a time-limited trial. Not stated means the pages I read named neither, even where there's a button inviting you to try it.
| Tool | Type | Good for | Free plan |
|---|---|---|---|
| Blumira | Security operations platform for IT teams | Small IT teams without a SOC | Trial only |
| Elastic Security | Agentic SIEM, EDR and XDR | Search-based detection at scale | Trial only |
| Graylog | SIEM and log management | Starting with open source logs | Yes |
| Microsoft Sentinel | Cloud-native SIEM | Organisations on Microsoft security tools | Trial only |
| Panther | AI SOC platform | An AI SOC on Databricks | Not stated |
| Rapid7 Incident Command | AI-powered next-gen SIEM | Pairing SIEM with managed detection | Not stated |
| Securonix | Unified defence SIEM with UEBA | Spotting abnormal user behaviour | Not stated |
| Splunk Enterprise Security | Threat detection, investigation and response | Large SOCs with mature processes | Not stated |
| Sumo Logic | Cloud log management and SIEM | Logs, monitoring and security together | Trial only |
| Wazuh | Open source XDR and SIEM | A free, open source starting point | Yes |
Ten SIEM tools to consider
Blumira
Best for: IT teams without a security operations centre that want alerts only when there's an actionable case to look at.
Elastic Security
Best for: Security teams that want SIEM, endpoint protection and automation on the Elastic search platform.
Graylog
Best for: Teams that want centralised log management and SIEM, starting with the open edition and scaling up later.
Microsoft Sentinel
Best for: Organisations already using Microsoft security products that want a cloud-native SIEM built for a leaner SOC.
Panther
Best for: Cloud-first security teams that want an AI SOC platform, now part of Databricks Lakewatch.
Rapid7 Incident Command
Best for: Security teams that want a next-gen SIEM alongside managed detection and response from the same company.
Securonix
Best for: Enterprises that want SIEM with behavioural analytics to detect abnormal human and AI activity.
Splunk Enterprise Security
Best for: Large security operations centres that want a unified threat detection, investigation and response platform.
Sumo Logic
Best for: Teams that want cloud log management, monitoring and SIEM tools in one place, with a trial of log analytics.
Wazuh
Best for: Small security teams that want open source SIEM and XDR, unified in a single agent and platform.
Open source, cloud-native or managed?
Open source SIEMs are powerful and flexible, but someone has to install, tune and maintain them. Cloud-native SIEMs run as a service and scale with your data. Managed or simplified platforms aim at IT teams without dedicated security analysts and focus on alerting only when there's something worth acting on.
Want AI doing the heavy lifting in your marketing?
I build the systems that handle the boring 80 percent, so you get your week back. Done properly, with the human kept in.
Be honest about who'll watch the alerts. A brilliant SIEM that nobody checks is worse than a simple one that somebody does.
Start with what you log
The NCSC says collecting logs is essential to understand how your systems are being used and is the foundation of security monitoring. Good logging lets you look back at what happened after a potential incident and understand its impact.
So decide your logging first: which systems, which events and how long you keep them. A SIEM can only analyse the logs you send it, and gaps you discover during an incident are the most painful kind.
Questions to ask SIEM vendors
- Which of our systems and cloud services does it collect logs from out of the box?
- How much tuning does it need before alerts become useful?
- Who triages alerts, us or your team?
- How long is data kept, and can we search older logs quickly?
- Does it include automated response, or alerting only?
- How do you handle growth in log volume?
Logs worth collecting first
- Sign-ins. Successes, failures and unusual locations.
- Admin changes. New accounts, permissions and settings.
- Email security. Phishing and malware detections.
- Cloud storage. Large downloads and sharing changes.
When a SIEM is too much
If you're a very small business with a handful of cloud apps, built-in security alerts and a managed security service may cover you better than running a SIEM. Revisit the decision as you grow or take on customers with security requirements.
Do you make SIEM tools? Tool makers can ask to be considered for a featured place on this list.
My plain advice on choosing a SIEM
Match the tool to the people you have. If you've got a small IT team and no security analysts, favour a platform that filters noise and tells you plainly what to do. If you've got engineers who enjoy tuning detection rules, open source can go a long way.
Run a trial with your real logs and a few test scenarios, such as a failed login burst, and see how fast each tool spots them. If your board's asking about security, my piece on board portals and cyber security covers that side of the conversation.
Frequently asked questions
What is a SIEM tool?
It's security software that collects logs and events from across your systems, correlates them and alerts you to signs of an attack or misuse.
Do small businesses need a SIEM?
Some do, especially if they handle sensitive data or must meet security standards. Others start with good logging and a simpler monitoring service.
Is there a free SIEM?
Yes. Some SIEMs offer open source editions you can run yourself. Check the free plan column in the table for each one.
What's the difference between SIEM and XDR?
A SIEM collects and analyses logs from many sources. XDR focuses on detecting and responding to threats across endpoints, networks and cloud, often from one vendor.
How long should security logs be kept?
It depends on your risks and any rules you must follow. Agree a retention period before you choose a SIEM, as it affects storage.
Who should watch SIEM alerts?
Someone named, with time set aside. That might be your IT team, a security analyst or a managed security provider.
