# RobotCheck.coffee

> Free machine-readability analyzer for websites. Checks how well AI crawlers, search bots, and LLMs can read any website. Returns a score 1–10 with actionable recommendations.

## What it does

RobotCheck.coffee analyzes any public website URL and checks 10 machine-readability criteria:

- **robots.txt** — Is the file present, properly structured, and does it allow AI crawlers?
- **llms.txt** — Does the site have a machine-readable service description for LLMs?
- **Sitemap XML** — Is there a valid sitemap with all important pages?
- **Schema.org Markup** — Structured data (JSON-LD, Microdata) for search engines and AI
- **Open Graph / Twitter Cards** — Social metadata for link previews
- **Semantic HTML** — Proper heading hierarchy, landmark elements (main, nav, header, footer)
- **Image Alt Texts** — Accessibility and AI-readability of images
- **Core Web Vitals** — Page load performance (LCP, FCP, Time to First Byte)
- **Canonical Tags** — Duplicate content prevention
- **Hreflang** — Multilingual page declarations

## Scoring

Each criterion is weighted and combined into a total score from 1–10. Rules for robots.txt, llms.txt and related HTTP/HTML signals come from primary sources (Anthropic, OpenAI, Google, llmstxt.org) and are updated weekly; some technical recommendations are shown as hints without affecting the score.

| Grade | Score |
|-------|-------|
| A+    | 9.0–10 |
| A     | 8.0–8.9 |
| B+    | 7.0–7.9 |
| B     | 6.0–6.9 |
| C     | 5.0–5.9 |
| D     | 4.0–4.9 |
| F     | below 4.0 |

## API

The analyzer is available via REST API:

- `POST /api/v1/analyze` — Analyze a domain (body: `{"domain": "example.com"}`), free, 5 checks per day per IP
- `POST /api/v1/check` — Same with an API key (`X-Api-Key` header), see [pricing](https://robotcheck.coffee/en/pricing)
- `GET /api/v1/rules-meta` — Current ruleset version and metadata
- `GET /api/v1/changelog-history` — Full version history of analysis rules

## Technology

- Backend: FastAPI (Python 3.12)
- Frontend: Next.js 16
- AI: Anthropic Claude API for rule generation
- Analysis rules: Updated weekly via automated pipeline
- Supported languages: German, English, French, Spanish, Italian, Dutch, Portuguese, Polish, Russian, Japanese, Chinese, Korean, Turkish, Swedish, Hungarian (15 languages)

## About

Built to help webmasters, developers, and SEO professionals understand and improve how AI systems perceive their websites. Free to use, no account required.

- Root URL: https://robotcheck.coffee
- Contact: andreas@diereuters.de

## Languages

Available languages: German (default, no URL prefix), English (/en), French (/fr), Spanish (/es), Italian (/it), Dutch (/nl), Portuguese (/pt), Polish (/pl), Russian (/ru), Japanese (/ja), Chinese (/zh), Korean (/ko), Turkish (/tr), Swedish (/sv), Hungarian (/hu).

- 15 languages with 7 pages each (home, check, pricing, changelog, blog, privacy, imprint)
- Blog articles: 4 pages each in German, English and Hungarian
- For the complete list of URLs, see the [sitemap](https://robotcheck.coffee/sitemap.xml): all pages with hreflang alternates

## Blog

- [The Cobbler and His Sitemap](https://robotcheck.coffee/en/blog/robotcheck-prueft-sich-selbst): a self-test of robotcheck.coffee and what an automated score misses
- [How LLMs Really Read Your Website](https://robotcheck.coffee/en/blog/wie-llms-deine-website-lesen): the 10 factors that decide whether ChatGPT, Gemini, Perplexity and Claude can read a site
- [llms.txt in 2026: What the Server Logs Actually Show](https://robotcheck.coffee/en/blog/llms-txt-2026-server-logs): which crawlers actually request llms.txt, based on real server logs
- [Why RobotCheck Updates Its Rules Automatically](https://robotcheck.coffee/en/blog/why-robotcheck-updates-its-rules-automatically): how the weekly rule pipeline works and why

## Optional

- [Homepage as Markdown](https://robotcheck.coffee/index.md): full homepage text as plain Markdown, see this file for details beyond this summary
- [Check your site](https://robotcheck.coffee/en/check): run a free analysis of any domain
- [Pricing](https://robotcheck.coffee/en/pricing): API key packages for automated and bulk checks
- [Changelog](https://robotcheck.coffee/en/changelog): version history of the analysis rules
- [Privacy Policy](https://robotcheck.coffee/en/privacy): data protection information
- [Imprint](https://robotcheck.coffee/en/imprint): legal notice