llms.txt vs robots.txt: Understanding the Difference

Both robots.txt and llms.txt are important for controlling how automated systems interact with your website, but they serve different purposes. What is robots.txt? robots.txt is a standard file that's been around since 1994. It tells search engine crawlers (like Googlebot, Bingbot) which pages they can and cannot access. robots.txt Purpose: • Control search engine indexing • Manage crawler bandwidth • Protect private sections • Standard since 1994 What is llms.txt? llms.txt is a newer standard specifically designed for AI systems and Large Language Models. It provides more detailed instructions for AI crawlers. llms.txt Purpose: • AI-specific instructions • Content policy definitions • Training data preferences • Summarization guidelines Key Differences: • Target: robots.txt → Search engines | llms.txt → AI systems • Age: robots.txt → Since 1994 | llms.txt → New standard • Specificity: robots.txt → Basic allow/disallow | llms.txt → Detailed AI policies • Format: robots.txt → Simple directives | llms.txt → Structured metadata How They Work Together: You need BOTH files for complete control: 1. robots.txt: Controls traditional search engines and basic AI crawler access 2. llms.txt: Provides detailed AI-specific instructions and policies When to Use Each: Use robots.txt for: Blocking search engines, managing crawl rate, standard SEO practices, legacy compatibility Use llms.txt for: AI crawler instructions, content policy definitions, LLM training preferences, AI-specific metadata Best Practices: • Always use both files for comprehensive control • Keep them consistent to avoid confusion • Update regularly as standards evolve • Test both files with validation tools