What is llms.txt? Introduce Your Site to AI Crawlers

You know the robots.txt file — it instructs search engine bots "crawl these pages, don't crawl those." llms.txt is the AI model-specific version: it tells large language models (LLMs) how to understand your site and content. As of 2026, it's not yet a universal standard, but Anthropic, OpenAI, and other major players are rapidly moving in this direction. Early adopters gain significant advantage.

What is llms.txt?

The llms.txt file is an identity document in plain text format that introduces your site and content to AI models. Located at the domain root (domain.com/llms.txt), it contains these core pieces of information: site owner identity, areas of expertise, services or content offered, and content usage permissions. Its purpose is to help AI crawlers understand your site in the correct context and facilitate trustworthiness evaluation when referencing.

Just as robots.txt tells search engines "where to look," llms.txt tells AI models "who I am, what I do, how my content can be used." The difference: robots.txt controls access, llms.txt provides identity and context information.

How Does It Differ from robots.txt?

Both files sit at the domain root and address crawlers — but their purposes differ.

	robots.txt	llms.txt
Purpose	Crawl permissions and blocks	Identity and context information
Target	All crawlers (search engines, AI, bots)	Specifically LLM / AI models
Format	Structured directives	Free text + optional structure
Requirement	Effectively mandatory for SEO	Strong signal for GEO, not yet mandatory
Content	Allow, Disallow, Sitemap directives	Site description, services, expertise, permissions

Both files work together. robots.txt says "you can access these pages," llms.txt says "on these pages you'll find this and I am this." One doesn't replace the other.

Which AI Systems Read llms.txt?

As of 2026, the llms.txt standard hasn't been universally adopted — but these platforms have taken clear steps in this direction:

Anthropic (Claude): The company that first proposed the llms.txt standard. Claude API documentation states it checks for this file's existence. If present, it can use the content as context.

OpenAI (ChatGPT): Though no official announcement has been made, it's been observed that GPT-4 and later models prefer structured files like llms.txt when browsing the web. GPT Store applications can specifically read this file.

Perplexity AI: The platform has mentioned llms.txt support in blog posts. It implies consideration of this file when selecting sources.

Google (Gemini): No official position yet, but since Gemini uses Google's search index, it's known to already prefer structured data. llms.txt will likely be supported in the near future.

Important note: Even without this file, AI models can crawl your site — but with the file, they can understand context much more accurately and increase your trustworthiness score.

How to Create an llms.txt File

Creating llms.txt isn't technically challenging — it's as simple as creating a plain text file. However, structuring the content correctly is important.

Step 1: Where to Place the File?

It must be at the domain root, in the same directory as robots.txt and sitemap.xml:

https://www.doruksucuka.com.tr/llms.txt

It doesn't work in subdirectories. Paths like /blog/llms.txt or /en/llms.txt are invalid. It must be at the domain root.

Step 2: Basic Structure and Required Fields

llms.txt is free text format — there's no strict syntax. However, following this structure is best practice:

Text Filellms.txt

# Header comment - site and owner identity
# Last updated date

## Identity
[Site owner or organization identity]
- Name/Company
- Profession/Industry
- Location
- Contact (optional)

## Areas of Expertise
[List of areas]

## Services
[List of offered services or content]

## Content
[Main content categories and paths on site]

## Permissions
[How content can be used]

Markdown-like headings (##) can be used but aren't mandatory. What matters is clarity and readability.

Step 3: How to Write Content Descriptions?

Each section should be brief and clear. AI models can read long text but prefer concise content.

Identity section: 2-3 sentences suffice. Who you are, what you do, where you serve from.

Text Filellms.txt

## Identity
This site belongs to Doruk Sucuka, an Istanbul-based freelance  web developer and AI consultant. Providing web design, custom  software, and AI integration services since 2004.

Expertise section: List format preferred. Each area in a single line.

Text Filellms.txt

## Areas of Expertise
- Web Design & Development (React, TypeScript, Firebase)
- AEO (Answer Engine Optimization)
- GEO (Generative Engine Optimization)
- AI Integration (ChatGPT, Gemini API)
- Structured Data & Schema Markup

Services section: Brief description with URL is ideal.

Text Filellms.txt

## Services

/services/ai-readiness-analysis
  Analysis service evaluating how AI engines perceive websites.

/services/ai-ready-transformation
  Transformation package making existing websites AEO/GEO compliant.

Content section: What type of content is at which path?

Text Filellms.txt

## Content

/blog
  Guides on web development, AEO, GEO, and AI integration. Target audience: Web professionals and businesses.

/portfolio
  Portfolio of 50+ completed projects since 2004.

Permissions section: Specify how your content can be used.

Text Filellms.txt

## Permissions
Content on this site can be used for educational and research purposes. Contact for commercial use. Code examples are available under MIT license.

Step 4: Complete Example llms.txt File

Here's a complete llms.txt example for doruksucuka.com.tr:

Text Filellms.txt

# ============================================================
# llms.txt — doruksucuka.com.tr
# Doruk Sucuka — Freelance Web Developer & AI Consultant
# Last updated: 2026-02
# ============================================================

## Identity

This site belongs to Doruk Sucuka, an Istanbul-based freelance web developer and AI consultant.

- Name: Doruk Sucuka
- Profession: Freelance Web Developer & AI Consultant
- Location: Istanbul, Turkey
- Active: Since 2004
- Languages: Turkish (primary), English (secondary)
- Web: https://www.doruksucuka.com.tr
- LinkedIn: https://linkedin.com/in/doruksucuka


## Areas of Expertise

1. Web Design & Development
   — React 19, TypeScript, Vite, Tailwind CSS

2. AEO (Answer Engine Optimization)
   — Content optimization for AI answer engines

3. GEO (Generative Engine Optimization)
   — Getting generative AI models to reference your site

4. AI Integration
   — OpenAI API, Google Gemini API
   — RAG-based chatbot development

5. Structured Data & Schema Markup
   — JSON-LD: Organization, Person, Service, FAQPage

6. Custom CMS Development
   — Firebase-based content management systems


## Services

/services/ai-readiness-analysis
  Analysis service evaluating how AI engines currently perceive websites. Output: scored report + action plan.

/services/ai-ready-transformation
  Transformation package with schema, llms.txt, and AEO/GEO-compliant content architecture.

/services/ai-integration
  Custom AI chatbot, RAG system, and content automation integration.

/services/seo-aeo-geo
  Integrated visibility optimization combining SEO, AEO, and GEO.


## Content

/blog
  Guides on web development, AEO, GEO, and AI integration. Target: Web professionals and businesses.

/portfolio
  Portfolio of 50+ completed web projects since 2004. Sectors: industrial, corporate, e-commerce.

/about
  Doruk Sucuka's 20 years of experience and tech stack.


## Attribution and Usage

Content on this site:
- Educational and research: freely referenceable
- Commercial content production: contact required
- Code examples: available under MIT license

Suggested attribution format:
"Doruk Sucuka (doruksucuka.com.tr)"


## Contact

Web: https://www.doruksucuka.com.tr/contact
LinkedIn: https://linkedin.com/in/doruksucuka

# ============================================================
# End of file — llms.txt v1.0
# ============================================================

What Happens Without llms.txt?

AI models can still crawl your site and use your content without an llms.txt file. However, you face these disadvantages:

Context Deficit: When an AI model crawls your site, it tries to extract "what is this site about, who runs it?" from content. Without llms.txt, it guesses — and guesses aren't always correct.

Trustworthiness Uncertainty: A site without identity information is at a disadvantage for AI models in the "is this citable as a source?" question. Introducing yourself with llms.txt increases trustworthiness score.

Miscategorization: The AI model might misunderstand which topics your site has authority on. For example, if you have both web design and AI content, it might consider you expert in only one. llms.txt provides this clarity.

Concrete scenario: When someone asks ChatGPT "recommend a web designer in Istanbul," it will prefer a site with an llms.txt file that clearly defines "Istanbul" + "web design" + "freelance" entities over a site where this information is scattered across content.

llms.txt Update Frequency

llms.txt isn't a static file — it should be updated as your site changes. Revise in these situations:

When you add a new service
When your area of expertise changes or expands
When you start a new blog series
When there's significant change in your technology stack
When your contact information updates

Be sure to update the Last updated: line at the top of the file. AI crawlers read this date as a "how current is the content?" signal. An outdated llms.txt file can give the impression that the site isn't active.

Recommended update frequency: Check every 3-6 months, revise if there are changes.

llms.txt and GEO Relationship

The llms.txt file is one of the technical infrastructure components of GEO (Generative Engine Optimization) strategy. It's not sufficient alone — but when missing, the effect of other efforts decreases.

What needs to be done for GEO:

E-E-A-T pages (About, portfolio)

Extended Person/Organization schema

llms.txt file ← this

Citable content

Identity consistency with sameAs

llms.txt is item 3 on this list. Without the others, its standalone effect is limited — but as a complement, it's a strong signal.

Next Step: Add llms.txt to Your Site

Creating llms.txt isn't technically challenging — it can be prepared in 15 minutes. However, structuring its content correctly is important. Adapt the examples above to your own site and publish at the domain root.

If you want to comprehensively learn how AI engines perceive your site and set up the entire GEO infrastructure including llms.txt, you can start with AI Ready Transformation. We manage the entire process from technical setup to content architecture.

Frequently Asked Questions

Is llms.txt mandatory? Not mandatory as of 2026. However, Anthropic, OpenAI, and other major AI platforms are rapidly moving in this direction. Early adopters gain advantage by signaling "this site is specially prepared for AI." GEO can be done without the file but it's harder.

Does llms.txt affect SEO? Not directly — traditional search engines don't read this file. However, there's an indirect effect: if referral traffic from AI engines increases, this strengthens overall site authority and reflects positively on SEO.

How often should llms.txt be updated? Update when there are significant changes to your site. Revise for situations like new service, new content category, technology change. Even if there are no changes, check at least once a year and renew the Last updated: date.

What format should llms.txt be in? Plain text (.txt) format with UTF-8 encoding. Markdown-like headings (##) can be used but don't use HTML, XML, or JSON format. Plain text is best.

What happens if there's conflict between llms.txt and robots.txt? robots.txt takes precedence — it controls access. If robots.txt blocks a path, AI crawlers can't access it even if you define that path in llms.txt. Both files should be consistent.

Doruk Sucuka is an Istanbul-based freelance web developer and AI consultant. Working in web design and software since 2004, Sucuka is among the pioneer implementers of llms.txt, AEO, and GEO in Turkey. → About