TEARDOWN 112 · REVIEWED 2026-08-21
SEOnaut
SEOnaut is an open-source technical SEO crawler that audits a site you point it at for broken links, redirect problems, missing or duplicate meta tags, and heading-order issues. It's free to self-host under the MIT license, with an optional low-cost hosted version for people who'd rather not run it themselves.
SEOnaut is the free, MIT-licensed, self-hostable answer already — its own Go-based crawl engine audits the single site you point it at, and the $9/month cloud tier only buys managed hosting and higher project/URL limits, not any extra capability.
Why people still pay
Worth the $9/month Growth tier instead of self-hosting if you'd rather not run and patch your own server — it buys managed hosting, recurring scheduled audits, and higher limits, not any capability unavailable in the free source code.
BUILD YOUR OWN · MOSTLY DONE ALREADY
There's nothing to build from scratch — the crawler is already public under the MIT license. The real one-shot task is standing up your own copy: clone the repo and run it via the project's own Docker Compose setup.
StackDocker + Docker Compose + MySQL + a reverse proxy (e.g. Caddy or nginx) for HTTPS — all wired together by SEOnaut's own compose file
Set up a self-hosted instance of SEOnaut (github.com/StJudeWasHere/seonaut, MIT license) on a VPS. Clone the repo, use its own docker-compose.yml to run the Go application and MySQL database, and set the required environment variables (database credentials, SMTP settings for notifications, and a crawler user-agent string) from the repo's example .env file. Put it behind a reverse proxy (Caddy or nginx) with HTTPS via Let's Encrypt, confirm the web UI loads, and create the first admin account through the sign-up flow.
QUESTIONS
Is the hosted version required, or can I really run this myself for free?
You can run it yourself for free — the Community tier is the same open-source code as the hosted version, deployable via the project's own Docker setup, with no feature held back for self-hosters.
Does the free cloud tier (Lite) have a catch?
It's capped at 1 project and 500 URLs, with no credit card required — fine for a single small site, but multi-site or larger-site auditing needs either the $9/month Growth tier or self-hosting.
Is there a proprietary index behind SEOnaut's reports, like a backlink database?
No — every audit is generated live from a crawl of the site you point it at. There's no historical web-scale database behind it, which is exactly why self-hosting it for free is realistic.