Open Source SEO Tools: A 2026 List With What Each One Does

Open source SEO tools let you read, run and change the code under each project's licence. That doesn't mean zero cost. Most tools here need a server, a Docker install or some Python, and a rank tracker still needs a paid data source or your own proxies to fetch search results.

Open-source projects matter for search in a second way too. A well-kept public repo is itself a discovery channel for developers and AI coding assistants, which our guide to GitHub READMEs as AI SEO fuel explains.

All 20 Open Source SEO Tools at a Glance

Each row was checked on the project's GitHub page on 30 September 2026. Where a project hasn't tagged a release recently, the table gives its latest commit too.

How this list was chosen

A project made this list of open source SEO tools if it met four rules on 30 September 2026:

1. Public source with a licence file. We read each project's LICENSE or COPYING file, not just the label on GitHub, and give the licence in the project's own words.
2. Active in 2026. A tagged release or a commit to the default branch this year. Dates come from each repo's release and commit feeds on GitHub.
3. An SEO job. The tool does one of the nine jobs above, not general web development.
4. Verified on its own page. Every description below comes from the project's README or docs.

Some well-known names fell out. The pytrends library for Google Trends data and Google's Schemarama validator are both archived, which on GitHub means read-only. A few "open source" SEO suites in other roundups had no public source repo we could match to their website. And free desktop tools with a closed codebase, however useful, are freeware rather than open source SEO tools.

Crawling, Audits and Link Checks

Crawlers are the core of most open source SEO tools lists, because a crawl finds the broken links, redirect chains and absent tags that cost rankings.

SEOnaut

SEOnaut (MIT, last commit 23 May 2026) calls itself an "open-source SEO auditing tool." It scans a site and sorts issues into critical, high and low, covering broken links, redirect problems, absent or duplicated meta tags and heading order. It's a Go web app with a MySQL database, and the project recommends Docker. There's also a hosted version at seonaut.org. Best for: a small team that wants a shared audit dashboard.

LibreCrawl

LibreCrawl (MIT, last commit 29 September 2026) is "a web-based multi-tenant crawler for SEO analysis and website auditing," built on Python Flask. It renders JavaScript with Playwright, extracts titles, descriptions and headings, maps internal and external links, pulls PageSpeed Insights data and exports to CSV, Excel, JSON or XML. Its repo pitches it as an open source alternative to Screaming Frog. Best for: crawling JavaScript-heavy sites on your own machine.

SiteOne Crawler

SiteOne Crawler (MIT, v2.6.1 on 29 June 2026) is a "website analyzer, cloner, and converter," now rewritten in Rust as a single binary for Windows, macOS and Linux. It writes an HTML audit report with a quality score from 0 to 10, generates sitemaps, and can convert a whole site to Markdown. A --ci flag fails a deploy when scores drop below your thresholds. Best for: developers who want audits inside their build pipeline.

advertools

advertools (MIT, 0.18.0 on 17 June 2026) is a Python package with a Scrapy-based SEO crawler, robots.txt and XML sitemap downloaders, a Google and YouTube SERP importer and a log file parser with reverse DNS lookup. Version 0.18.0 added serp_claude, which records the pages, ranks and cited domains that Claude's web search returns through Anthropic's API. You supply your own API key, and API results come from a different surface than the Claude apps. Best for: analysts who live in notebooks.

lychee

lychee (MIT or Apache 2.0, your choice; v0.24.2 on 1 May 2026, with nightly builds since) is a "fast, async, stream-based link checker written in Rust." It checks links in websites, Markdown and HTML files, and ships as a command-line tool, a library and a GitHub Action. Best for: catching broken links in docs before they go live.

Logs, Rank Tracking and Keyword Research

These open source SEO tools answer three questions: who is crawling you, where you rank, and what your pages are about.

GoAccess

GoAccess (MIT, v1.12 on 16 September 2026) is a "real-time web log analyzer" that runs in a terminal or as a live HTML dashboard. It reads Apache, Nginx, CloudFront and other log formats. Its README says it "keeps AI crawlers and Fediverse (ActivityPub) traffic in their own categories, separate from traditional search engine crawlers," which makes it a quick way to see GPTBot and ClaudeBot hits. Best for: anyone with server access who wants answers in minutes.

SerpBear

SerpBear (MIT, v3.1.0 on 27 March 2026) is an "Open Source Search Engine Position Tracking and Keyword Research App." It tracks keyword positions in Google for unlimited domains and keywords, emails you when they move, and connects to Search Console for real clicks and impressions. Positions come from a third-party scraping API or proxies you supply, so budget for that service. Best for: replacing a paid rank tracker for a handful of sites.

SEO Panel

SEO Panel (GPL v2, 6.0.0 on 26 March 2026) is a PHP and MySQL "seo control panel" for managing many websites. Its README lists a keyword position checker, site auditor, backlink checker and Moz rank checker. It also lists an automatic directory submission tool; Google's link spam policy covers "using automated programs or services to create links to your site," so leave that feature off. Change the default admin password on install, as the README says. Best for: agencies on shared PHP hosting.

KeyBERT and YAKE!

KeyBERT (MIT, v0.9 on 7 February 2025, commits through 25 August 2026) uses BERT embeddings to find "keywords and keyphrases that are most similar to a document." YAKE! (AGPL v3 or later, with a commercial licence from INESC TEC; 0.7.3 on 9 February 2026) extracts keywords from text statistics, with no training data or dictionaries, in many languages. Both work on text you give them rather than search data, so they show what your own pages, or a rival's, are about. Best for: content audits and topic maps.

Structured Data, robots.txt and Site Speed

The next group of open source SEO tools handles the technical layer: schema, crawler rules and page speed.

extruct and schema-dts

extruct (BSD 3-Clause, v0.18.0 on 8 November 2024, commits through 27 September 2026) pulls JSON-LD, Microdata, RDFa, Open Graph, Microformats and Dublin Core out of HTML, which makes it handy for auditing schema markup across a crawl. schema-dts (Apache 2.0, v2.0.0 on 23 March 2026) gives TypeScript types for Schema.org JSON-LD, so errors show up in your editor. Its README notes it's "not an officially supported Google product." Best for: developers who generate schema in code.

Google's robots.txt parser

Google's robots.txt parser (Apache 2.0, stable tag on 20 February 2026, last commit 1 April 2026) is "slightly modified … production code used by Googlebot." It includes a small binary to test one URL and user agent against a robots.txt file. Best for: settling arguments about how Google reads a tricky rule.

ai.robots.txt

ai.robots.txt (MIT, v1.52 on 7 September 2026) is a community list of "AI-related crawlers of all types, regardless of purpose," shipped as robots.txt, .htaccess, Nginx, Caddy, HAProxy and lighttpd rules. Its robots.txt on 30 September 2026 had 180 user agents, including OAI-SearchBot, ChatGPT-User, Claude-SearchBot, PerplexityBot and Applebot. OpenAI says sites that block OAI-SearchBot won't be shown in ChatGPT search answers except as navigational links, so edit the list to your goals. Our AI crawler directory explains which bot does what. Best for: sites that want to opt out of AI crawling deliberately.

Lighthouse, Unlighthouse and sitespeed.io

Lighthouse (Apache 2.0, v13.5.0 on 18 September 2026) "analyzes web apps and web pages, collecting modern performance metrics" and best-practice checks, from Chrome DevTools, a CLI or a Node module. Unlighthouse (MIT, v0.19.0 on 29 September 2026) runs Lighthouse across "your entire site" with one npx command. sitespeed.io (MIT, 42.7.0 on 11 September 2026) produces reports with Core Web Vitals, a load video and a waterfall, and can run on a schedule. Best for: Lighthouse for spot checks, Unlighthouse for full-site sweeps, sitespeed.io for trends.

Analytics

Analytics closes the loop on the other open source SEO tools, because it shows whether your fixes brought visits.

Matomo, Plausible CE and Umami

Matomo (GPL v3 or later, stable 5.14.0 on 21 September 2026) is a PHP and MySQL analytics platform that aims to be "a Free software alternative to Google Analytics." Plausible Community Edition (AGPL v3 or later, with its tracker script under MIT; v3.2.1 on 1 June 2026) is a "privacy-first," cookie-free analytics tool you can self-host. Umami (MIT, v3.4.0 on 17 September 2026) covers traffic, campaigns and conversions without cookies, on Node.js and PostgreSQL. Best for: Matomo if you need depth, Plausible or Umami if you want a single page of stats.

The Open Source SEO Starter Stack

Picking open source SEO tools is easier by team than by feature. We call this the starter stack: the smallest set that covers crawling, speed, logs and analytics for each kind of team.

Add SerpBear to any row if you track rankings, and pair every row with Google Search Console, which is free but not open source. For AI visibility trackers, which are almost all paid, see our GEO tools list.

Rankbox isn't open source. It's a paid AI writer that researches the live web and drafts source-backed articles, on the Business plan at $49.50 a month with a 7-day trial (pricing). Its free tools, such as the AI crawler log analyzer and robots.txt tester, are free to use but not open source.