When the AI-Ready reachability test shows GPTBot and ClaudeBot as 403 Blocked with a Cloudflare marker detected, the block comes from a setting in front of your site, not from the website itself.
Why this happens. The most common cause is the Block AI bots setting in Cloudflare, which Cloudflare enables for many domains by default.
How to fix it in Cloudflare.
- Sign in to Cloudflare and open your domain.
- Go to Security, then Settings, and find Block AI bots under Bot traffic.
- Set it to Do not block. If you want to keep other AI scrapers blocked, leave that setting on and instead open AI Crawl Control, then Crawlers, and set GPTBot and ClaudeBot individually to Allow.
- Wait a minute, then run the reachability test again. Both crawlers should return 200.
If your Cloudflare account is managed by your hosting provider or agency, contact their support and ask them to change the setting for you.
If the test still shows 403. The hosting server’s bad-bot list may also name these crawlers. On hosted sites, GPTBot, ClaudeBot, and ChatGPT-User can be allowed in that list while the rest of the bad-bot filter stays on.
ChatGPT-User is the fetcher ChatGPT uses when a person asks it to open a page. The list names it separately, so ask your host to check it even when the main reachability test passes.