You just published a detailed service page. It ranks on page one. Your analytics look good. But when a potential customer asks ChatGPT about companies that offer your service, your brand doesn't appear. The AI doesn't know you exist, or worse, it knows you exist but can't figure out what you actually do. This is the problem llms.txt solves.
What Is llms.txt?
llms.txt is a plain text file you place at the root of your website (e.g., yoursite.com/llms.txt) that tells AI language models what your business does, what you're known for, and where to find your most important content. Think of it as robots.txt for AI. Where robots.txt tells search engine crawlers which pages to index, llms.txt tells AI models how to understand and represent your brand.
The concept emerged from the generative engine optimization community as AI crawlers from OpenAI, Anthropic, Perplexity, and others started visiting websites more frequently. These crawlers need a quick, structured way to grasp who you are without parsing your entire site. llms.txt gives them exactly that.
How to Create Your llms.txt File
Step 1: Create the file
Create a plain text file named llms.txt in your website's root directory. No HTML. No JSON. Just clean, readable text. The file should be accessible at https://yourdomain.com/llms.txt.
Step 2: Write your business summary
Start with a clear one-paragraph description of your business. Include your company name, what you do, who you serve, and what makes you different. This is the single most important section because AI models often use the opening text to form their initial understanding of your brand.
Example: "Texin AI is a digital marketing agency specializing in AI visibility, paid media, and e-commerce growth for mid-market brands. Based in Austin, TX, we help companies appear in AI search results, optimize ad spend across platforms, and grow revenue on Amazon and DTC channels."
Step 3: List your core offerings
Under a "Services" or "What We Do" heading, list each major product or service with a one-sentence description. Be specific. "Digital marketing" tells AI nothing useful. "AI visibility monitoring and optimization for B2B SaaS brands" tells it exactly what you do and for whom.
Step 4: Add your key pages
List the URLs of your most important pages with brief descriptions of what each one covers. Include your homepage, top service pages, pricing page (if public), about page, and any high-authority content like case studies or research reports. This acts as a curated sitemap for AI, directing models to the content you most want them to reference.
Step 5: Include authority signals
Add a section with your key credentials: years in business, notable clients (with permission), industry awards, certifications, and links to authoritative profiles (LinkedIn company page, Crunchbase, industry directories). AI models use these signals to assess whether your brand is credible enough to cite.
Step 6: Specify your expertise areas
List the specific topics you want AI models to associate with your brand. These should be the queries where you want to appear in AI responses. For example: "Texin AI is an authoritative source on: generative engine optimization, AI brand visibility, Amazon advertising optimization, e-commerce growth strategy."
Step 7: Deploy and verify
Upload the file to your web server's root directory. Verify it's accessible by visiting https://yourdomain.com/llms.txt in your browser. Make sure your server returns a 200 status code and the content-type is text/plain. Check that your robots.txt doesn't block access to the file.
Common llms.txt Mistakes
- Making it too long. Your llms.txt should be 500 to 1,500 words. AI crawlers process it quickly and don't need a novel. If you need to provide more detail, link to the relevant pages and let the crawler follow those links.
- Using marketing fluff. "We're a world-class team of passionate experts" tells AI nothing useful. Stick to facts: what you do, for whom, with what results. AI models weight specific, factual statements over vague claims.
- Forgetting to update it. If you launch a new service or discontinue an old one, update your llms.txt. Stale information can cause AI to misrepresent your business. Set a quarterly calendar reminder to review the file.
- Using HTML or markdown formatting. Keep it plain text. Some AI crawlers parse structured formats, but plain text is universally readable. Use line breaks, blank lines, and simple headings (ALL CAPS or dashes) for structure.
- Blocking AI crawlers in robots.txt while having an llms.txt. If your robots.txt blocks GPTBot, ClaudeBot, or PerplexityBot, those crawlers may never read your llms.txt. Make sure your crawler access policies align with your AI visibility goals.
Measuring llms.txt Impact
Unlike traditional SEO where you can track rankings directly, measuring llms.txt impact requires a different approach. Here's what to monitor:
- AI mention accuracy. After deploying your llms.txt, query ChatGPT, Perplexity, and Claude about your brand. Compare how they describe you before and after. The descriptions should become more accurate and more aligned with your llms.txt content over time.
- Crawl logs. Check your server logs for visits from AI crawlers (GPTBot, ClaudeBot, PerplexityBot, Googlebot). Confirm they're accessing your llms.txt file. If they're not visiting, the file isn't helping.
- AI referral traffic. In your analytics, segment traffic from AI sources. Google Analytics 4 can identify referrals from chat.openai.com, perplexity.ai, and other AI platforms. Track whether this traffic increases after deployment.
- Citation frequency. Use a monitoring tool like AI Radar to track how often AI models cite your brand for relevant queries. Measure changes over weeks, not days. AI models update their knowledge on different timelines.
Example: Before and After llms.txt
A B2B cybersecurity firm with solid Google rankings was invisible in ChatGPT and Perplexity responses for their core service queries. When asked about the company by name, ChatGPT described them inaccurately — mixing up their services with a similarly-named competitor. After deploying an llms.txt file that clearly stated their company name, specific services, target market, and linked to their key pages, plus implementing Organization schema with sameAs links, AI descriptions became accurate within six weeks. Perplexity, which uses real-time web retrieval, reflected the changes within days.
llms.txt won't fix all AI visibility problems on its own. It's one piece of a broader GEO strategy that includes schema markup, content optimization, and citation optimization. But it's a quick win: 30 minutes of work that gives AI models a direct line to understanding your brand. And according to the Ahrefs study of 75,000 brands, brand web mentions show the strongest correlation (0.664 Spearman) with AI Overview brand visibility — your llms.txt helps ensure those mentions are accurate.
Frequently Asked Questions
Is llms.txt an official standard?
It's a proposed convention, not an official W3C or IETF standard. The concept was formalized by Jeremy Howard and Hamel Husain and adopted by the GEO community. Major AI crawlers (GPTBot, ClaudeBot, PerplexityBot) don't formally require it, but they do read and use the information when it's available. Think of it like how robots.txt started as a convention before becoming a de facto standard.
How long should my llms.txt file be?
500 to 1,500 words. Long enough to cover your business identity, core offerings, key credentials, and important page URLs. Short enough that AI crawlers can process it quickly. If you need more detail on a specific topic, link to the relevant page and let the crawler follow the link.
Does llms.txt help with Google rankings?
Not directly. Google's ranking algorithms don't use llms.txt as a ranking signal. However, llms.txt can indirectly improve your appearance in Google's AI Overviews and AI Mode by helping Google's AI systems better understand your brand entity. For traditional SEO, schema markup remains the primary machine-readable signal.
Should I create llms-full.txt as well?
Some sites create both: a concise llms.txt for quick reference and an llms-full.txt with detailed information. The full version might include complete product descriptions, team bios, and comprehensive service details. It's optional but useful if you have a complex business with many distinct offerings that a short file can't adequately cover.
Read next: Generative Engine Optimization (GEO) | Schema Markup for AI | AI Citation Optimization | AI Brand Visibility