Deploys regenerate robots.txt. Developers "clean up" old entries. Agencies overwrite the AI-bot block you carefully wrote. The diff catches every change across robots.txt, ai.txt, and llms.txt in one pass — critical when AI-crawler allow-list drift can cost you AEO citations overnight.
Read the story behind this tool: A Deploy Silently Blocked GPTBot Last Week And Nobody Noticed →
Paste the old + new contents of each file (leave blank if unchanged). Or paste "Before" URL and "After" URL to auto-fetch both.