OpenSEO is an open source SEO tool that replaces Semrush and Ahrefs. You do keyword research (volume, difficulty, intent), analyse a competitor and its backlinks, track your rankings and run a technical audit of your site. It also measures your brand's visibility in ChatGPT style answers, and through MCP you can query it from Claude or Cursor. If you would rather host nothing, the hosted version costs around €9 a month, credits included. The thing to understand: the software is free, but the data comes from DataForSEO, which you pay as you go with your own key (about 5 cents per keyword research, 8 cents per domain overview, a minimum top up of about €45). For a small site, that is a few euros a month.
Versus Semrush: the match
Price
OpenSEO
€0 for the tool, data pay as you go (a few cents per request)
Semrush
€134/month, €113 yearly
Tracked keywords
OpenSEO
As many as you want, you pay per request
Semrush
500 on the SEO plan
Keyword research
OpenSEO
Volume, difficulty, intent, SERP
Semrush
Yes, proprietary database
| VS | OpenSEO | Semrush ↗ |
|---|---|---|
| Price | €0 for the tool, data pay as you go (a few cents per request) | €134/month, €113 yearly |
| Tracked keywords | As many as you want, you pay per request | 500 on the SEO plan |
| Keyword research | Volume, difficulty, intent, SERP | Yes, proprietary database |
| Backlinks | Yes, via DataForSEO | Yes, proprietary database |
| AI visibility | ChatGPT mentions and citations, prompt explorer | As an add on, on higher plans |
| From Claude or Cursor | Yes, built in MCP server | No |
| Where your data lives | At home (Docker) or on your Cloudflare account | At Semrush |
How to install it (even from zero)
Two paths: Docker on your machine to try it (no authentication, do not expose it as is), or Cloudflare, free, to reach it from anywhere. Either way you need a DataForSEO key, which the prompt has you create.
- 1
Paste this prompt into Claude (Code or Desktop)
It asks where to install, walks you to the DataForSEO key, starts OpenSEO and has you run your first keyword research:
Je veux installer OpenSEO (outil SEO open source, dépôt GitHub every-app/open-seo, site openseo.so) à la place de Semrush ou Ahrefs. Demande-moi d'abord si je veux l'essayer sur ma machine avec Docker (docs/SELF_HOSTING_DOCKER.md du dépôt) ou l'héberger sur Cloudflare avec le plan gratuit (docs/SELF_HOSTING_CLOUDFLARE.md), puis suis la doc officielle pas à pas. Guide-moi pour créer un compte DataForSEO et une clé d'API (docs/DATAFORSEO_API_KEY.md), en me prévenant que les données se paient à l'usage avec un dépôt minimum de 50 dollars, et mets la clé dans le fichier .env. En mode Docker, rappelle-moi que l'application tourne sans authentification et ne doit pas être exposée sur internet sans protection. Si je veux les fonctions IA, propose-moi d'ajouter une clé OpenRouter. Lance l'outil, ouvre-le dans mon navigateur, et fais-moi faire une première recherche de mots-clés sur mon domaine pour vérifier que les données arrivent. Explique-moi comment suivre ma consommation chez DataForSEO et comment mettre OpenSEO à jour. Review the GitHub repository and check whether it is safe to install given my machine and my infrastructure. Ask me as many questions as possible, using widgets, to clarify my request and be as precise as you can.
- 2
Create your DataForSEO key
Free account, minimum top up of 50 dollars (around €45), then every request is deducted. A dashboard on their side shows what you spend.
- 3
Wire it to Claude
OpenSEO exposes an MCP server: add it to Claude or Cursor and ask "which keywords can my site target?" without opening the interface.
Paste this prompt into Claude (Code or Desktop)What you actually do with it
Find the keywords for your next piece of content
Type a topic, see the volume, the difficulty and who already ranks. Five cents a search, instead of a three figure subscription.
Watch your rankings and backlinks
Your keywords tracked over time, the sites that link to you, the ones that link to your competitors: enough to know where to push.
Know whether AIs talk about you
Is your brand cited in ChatGPT answers? OpenSEO checks it prompt by prompt, a feature the paid tools sell as an add on.
Project health, at a glance
Before installing an open-source tool, one question matters: is the project alive? These scores are computed from public GitHub data. They are not made up.
86/100
ExcellentVery active, well-maintained project: go ahead with confidence.
- Activity
- 100
Is the code moving? (commits in the last 30 days)
- Maintenance
- 100
How fresh is the latest update? Fresher is better.
- Community
- 77
Stars and contributors: people around means help and fixes.
- Maturity
- 55
Project age. Old enough to be solid, still alive.
- Momentum
- 100
Current pace versus its usual pace: speeding up or dozing off?
The repo in numbers
- GitHub stars
- 25.9k
- Forks
- 3.5k
- Contributors
- 20
- Commits
- 926
- Project age
- 0.7 yrs
- Last commit
- today
- Size
- 35.6 MB
- License
- MIT
Built with
- TypeScript 93.6%
- MDX 4.4%
- JavaScript 1.2%
- CSS 0.6%
Scores computed automatically from the GitHub API (last-30-days activity, update freshness, community size, project age). Refreshed daily.
Loucash’s take
7/10
If you pay Semrush or Ahrefs for one or two sites, OpenSEO covers the essentials: keywords, backlinks, rankings, audit, plus AI visibility and an MCP server to do your SEO from Claude. The software is truly free and open source, and it even runs on Cloudflare's free plan. What I like: the project's pace (19,000 stars in under seven months, a release every couple of weeks), pay per request rather than a subscription, and the AI angle nobody else offers in open source. What may bite: it is not free end to end. The data comes from DataForSEO, you need an account and a minimum top up of 50 dollars (around €45), then every request is deducted (a few cents). For a small site that is a few euros a month, but if you fire a thousand requests a day, do the maths. The project is young (version 0.1), the Docker version runs without a password and must never be exposed as is, and the AI features need an extra OpenRouter key.
It’s for you if: You do SEO for one or two sites, you pay Semrush or Ahrefs for a few searches a week, and you want your data at home. If you run thousands of requests a day, compare the pay as you go cost first.
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