Free llms.txt Validator & Tester
Instantly check your file for syntax errors, compliance with the official standard, and readability for AI agents like ChatGPT and Claude.
We will check for /llms.txt automatically if not specified.
Structure Check
Verifies H1 headers, summaries, and correct Markdown syntax.
Link Validation
Ensures you have valid navigation links for AI agents to follow.
Standards Compliant
Checked against the official standard proposed by Answer.AI.
How to validate your llms.txt
The llms.txt standard is strict about formatting to ensure AI agents (like ChatGPT, Claude, and Perplexity) can parse your content efficiently.
- 1File Location — Must be at the root (e.g., example.com/llms.txt).
- 2Structure — Must start with an H1 (# Title) followed immediately by a Blockquote (> Summary).
- 3Syntax — Links must use standard Markdown `[Title](URL)` format.
Common Validation Errors
Missing Blockquote Summary
AI agents use the blockquote to quickly understand your site's purpose without reading the whole file.
Incorrect Content-Type
Your server must serve the file as text/plain or text/markdown.
No H2 Sections
Grouping your links into sections (e.g., ## Documentation) helps AI categorize your resources.
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