Security Onion vs Wazuh: Which Open-Source Security Platform Fits You? (2026)

Security Onion is a network-security-monitoring distribution - a full platform you deploy as a grid of manager, sensor, and search nodes. Sensors watch traffic and generate logs; everything flows into the Elastic Stack, surfaced through the Security Onion Console (SOC) for alerts, dashboards, hunting, cases, and grid management. It scales from a single appliance to a thousand-node grid and has been downloaded over 2 million times.

Wazuh is a host-centric unified XDR + SIEM. A lightweight agent on each endpoint sends telemetry to the Wazuh server (decoders, rules, correlation), which forwards analyzed data to the Wazuh indexer (an OpenSearch fork) and dashboard. A fork of OSSEC (2015), it deploys single-node or clustered and scales to tens of thousands of agents.

This is Security Onion's core strength: signature-based NIDS via Suricata, rich protocol metadata via Zeek (or Suricata), full packet capture (Stenographer or Suricata PCAP), file analysis via Strelka, and OpenCanary intrusion-detection honeypots. Few open-source stacks match this network depth in one installer.

Wazuh is not a network monitoring tool: it has no built-in NIDS or full packet capture. It can ingest network-device logs agentlessly via syslog/SSH/APIs, but it doesn't inspect traffic or store packets, so network-level detection is a gap you'd fill with another tool.

Security Onion's host layer is the Elastic Agent (data collection, live queries via osquery, centralized management via Elastic Fleet). Notably, in Security Onion 2.4+ Elastic Agent replaced the earlier osquery, Beats, and Wazuh components - so Security Onion no longer bundles Wazuh as its HIDS. Host coverage is capable but secondary to its network focus.

Endpoints are Wazuh's home turf. Agents run on Linux, Windows, macOS, Solaris, AIX, and HP-UX, delivering file integrity monitoring, host intrusion/rootkit detection, security configuration assessment, software inventory, and active response, with deep Windows coverage (event logs, registry, VirusTotal, YARA).

Security Onion focuses on detection, hunting, and forensics rather than compliance dashboards; you can build compliance views from its data, but it doesn't ship prebuilt regulatory modules or CVE-based vulnerability scanning as a headline feature.

Wazuh has built-in compliance dashboards for PCI DSS, GDPR, HIPAA, and NIST 800-53, plus automated vulnerability detection (correlating agent software inventory against CVE feeds) and CIS-benchmark security configuration assessment - often the deciding factor for regulated organizations and MSPs.

Security Onion centralizes logs into the Elastic Stack (Elasticsearch/Logstash/Kibana) and can act as a syslog destination for other sources, with its own SOC interfaces for alerting, dashboards, and hunting. It's a capable SIEM, strongest when network data is part of the picture.

Wazuh provides SIEM-style log collection, decoding, correlation, and retention in its OpenSearch-based indexer, with 5000+ built-in rules mapped to MITRE ATT&CK and extensive decoders for common software and cloud services (AWS, Azure, GCP, M365, GitHub).

Security Onion shines here: full packet capture lets analysts reconstruct sessions, Strelka analyzes extracted files, and bundled analyst tools (Wireshark, NetworkMiner via the Desktop option) plus SOC case management support deep DFIR - the reason it's a staple in SANS courses and threat-hunting exercises.

Wazuh supports hunting through rules, decoders, log archives, and MITRE ATT&CK mapping, and active response for containment, but without packet capture its forensic depth on the network is limited to logged telemetry.

Security Onion is a free and open platform, though it combines components under mixed licenses (BSD, GPL, Apache, and the Elastic License 2.0) - the latter being source-available rather than OSI open source. Commercial options (appliances, Pro license, training, support) fund the project.

Wazuh's core engine is GPLv2 with the indexer/dashboard on Apache-2.0 OpenSearch, and there's no paid tier gating features - every capability is free to self-host. Wazuh Inc. monetizes via optional Wazuh Cloud and professional support. This 'no feature gating' purity appeals to teams that weigh open-source licensing carefully.

Security Onion is a full distribution (Oracle Linux 9 base) deployed as Import/Evaluation/Standalone/Distributed grids. Production needs dedicated network sensor hardware (SPAN/TAP, CPU-heavy Suricata/Zeek), so it's more infrastructure to plan; Security Onion Solutions sells matched appliances.

Wazuh installs the manager, indexer, and dashboard from a single all-in-one installer in roughly 10 - 15 minutes on a correctly sized host, then you enroll agents. It scales horizontally later. Both, however, demand real tuning - out-of-the-box rules are noisy until adapted.