CodeQuest.workSEO

AI Search SEO llms.txt Checker

Is your site properly recognized by ChatGPT, Perplexity, and Gemini?Diagnose your llms.txt setup — the first step in GEO, AIO, AEO & LLMO optimization.

Available on Basic plan and above with auto code generation

What Is AI Search Optimization (GEO/AIO/AEO/LLMO)?

AIO (AI Optimization), GEO (Generative Engine Optimization), AEO (Answer Engine Optimization), LLMO (Large Language Model Optimization) — the key to all of them is llms.txt.

Gateway to AI Search

If robots.txt controls crawler access, llms.txt serves as a content guide for AI. It efficiently communicates your key pages to AI crawlers.

Format Validation

Checks for H1 title, description text, and Markdown links. Automatically validates whether your file follows the specification.

.well-known Support

Verifies /.well-known/llms.txt path configuration (Pro plan). Ensures AI crawlers can reliably discover your file.

Auto Template Generation

Analyzes your site's title, description, and internal links to auto-generate a recommended llms.txt template. Copy & paste to deploy instantly.

Why AI Search Optimization (GEO/AIO) Matters

Since 2025, AI search engines like ChatGPT, Perplexity, and Gemini have rapidly gained adoption. Beyond traditional SEO (meta tags, structured data), GEO (Generative Engine Optimization) and AIO (AI Optimization) — collectively known as AI search optimization — are becoming new SEO essentials.

By adding llms.txt, AI crawlers can efficiently discover and understand your key pages. This increases the chances of your brand and services appearing accurately in AI search results, driving new traffic through AI channels. The llms.txt specification is a cutting-edge practice not yet implemented by many SEO tools.

Recommended next steps

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Structured Data Check

Diagnose Schema.org / JSON-LD implementation

Query Fanout Checker

Check readiness for AI search query fanout

Core Web Vitals

Measure LCP, CLS and INP for speed and stability

Start AI search optimization

Diagnose your llms.txt setup

llms.txt check and auto code generation available on Basic plan and above.

Try SEO Check too →

FAQ

What is llms.txt?▾
llms.txt is a Markdown file that helps AI crawlers (ChatGPT, Perplexity, Gemini, etc.) efficiently understand your website. While robots.txt controls crawler access, llms.txt serves as a content guide for AI. Place it at your site root (/llms.txt).
What are the benefits of having llms.txt?▾
AI search engines (ChatGPT, Perplexity, etc.) can more efficiently discover and understand your key pages. This increases the chances of your brand and service information appearing accurately in AI search results.
What is .well-known/llms.txt?▾
/.well-known/llms.txt is a recommended path in the llms.txt specification. Placing the same content at both /llms.txt and /.well-known/llms.txt ensures AI crawlers can reliably discover the file. Pro plan checks this configuration.
How do I write llms.txt?▾
Write in Markdown format. Use H1 for site name, blockquote for description, and H2 sections for key page lists. Select 10-20 important pages and list them as [Page Name](URL) links. Our code generation feature auto-creates a recommended template.
Is the llms.txt check free?▾
The llms.txt check is available on Basic plan and above. Basic checks file existence, H1 title, and Markdown links. Pro also checks .well-known configuration. Code generation creates recommended llms.txt templates automatically.
What are AIO, GEO, AEO, and LLMO?▾
These are all terms for AI search optimization. AIO (AI Optimization) covers general AI search optimization, GEO (Generative Engine Optimization) targets generative AI search, AEO (Answer Engine Optimization) focuses on answer engines, and LLMO (Large Language Model Optimization) targets LLMs specifically. Setting up llms.txt is a foundational practice common to all of these.

What is llms.txt — A Site Guide for AI

/llms.txt is a proposed specification that provides AI crawlers and LLMs with a site overview and links to key content in Markdown format. Think of it as an AI-oriented counterpart to robots.txt — designed to help AI better understand your site.

Placed at /llms.txt in the site root, it is intended to function as a guide page that AI crawlers can reference first when visiting your site. A companion file /llms-full.txt containing more detailed content is also proposed as an extended variant.

Minimal llms.txt Sample

# Site Name
> Describe your site in 1–2 sentences.

## Docs
- [Page Title](https://example.com/page): Brief description

## Optional
- [Supplementary Page](https://example.com/sub)

Elements to include:

  • Use H1 (#) for your site name
  • Use a blockquote (>) to summarize your entire site in 1–2 sentences
  • Organize links to key content under ## sections
  • Add a brief description after a colon for each link

3 Use Cases for llms.txt

Present your site's key points to AI in GEO/AI search contexts

When AI search engines like ChatGPT or Perplexity crawl your site, having an llms.txt helps them efficiently understand your site's overview and key content. It serves as an experimental early-adoption measure to increase the chance that your site is included as a citation target.

Explicitly guide AI to your main content

By listing links to your important pages by section in llms.txt, you can guide AI on which content to prioritize. Larger sites especially benefit from making key pages less likely to be overlooked.

Supplement AI comprehension alongside structured data

While JSON-LD structured data targets Google's crawler, llms.txt plays a complementary role in describing your site in natural language for AI crawlers. Maintaining both improves the comprehensiveness of information available to crawlers.

An honest note: llms.txt is an unofficial proposed specification still in the advocacy stage. Major AI providers such as Google and OpenAI have not officially stated that they reference it. Adopting it is an experimental early-adoption step, and no guaranteed effect on search rankings or AI citations should be expected. Consider it a low-risk, forward-looking measure.