Short answer
OpenAI publishes IP ranges at openai.com/searchbot.json, gptbot.json, chatgpt-user.json and adsbot.json. Combine user-agent matching with these lists, and refresh them automatically: OpenAI warns not to rely on short-term IPs seen in logs.
Approach
- Match user agent
- Check IP against the current JSON list
- Refresh the list on a schedule
- Prefer provider-level verified-bot features where available
Questions
Does Google publish lists?
Yes, Google publishes crawler IP ranges and supports reverse DNS verification.
Facts checked against the sources below on 12 October 2026. Platforms change quickly: if something here no longer matches what you see, tell us and we will update it.
