ptt.cc: what it tells AI crawlers

On 26 October 2026, ptt.cc had no robots.txt, so no AI crawler was disallowed.

Last verified 2026-10-26 21:13 UTC (daily run of 2026-10-26). Proof for that day.

Panel
top 10k (Tranco)
robots.txt
absent (HTTP 404) · https://www.ptt.cc/robots.txt
unchanged since 2026-10-26

Per AI bot, 2026-10-26

User agentVerdictHow
GPTBotallowsno applicable rules
OAI-SearchBotallowsno applicable rules
ChatGPT-Userallowsno applicable rules
ClaudeBotallowsno applicable rules
Claude-SearchBotallowsno applicable rules
Claude-Userallowsno applicable rules
PerplexityBotallowsno applicable rules
Perplexity-Userallowsno applicable rules
Googlebotallowsno applicable rules
Google-Extendedallowsno applicable rules
Applebot-Extendedallowsno applicable rules
CCBotallowsno applicable rules
Bytespiderallowsno applicable rules
Meta-ExternalAgentallowsno applicable rules
Amazonbotallowsno applicable rules

Other signals

Publishes /llms.txtno
Publishes /ai.txtno
Publishes /.well-known/tdmrep.jsonno
Reserves TDM rights (TDMRep file, header or meta)not observed
Declares Content Signals (robots.txt or header)not observed
Says ai-train=no in a Content Signalnot observed
Points to an RSL licence (robots.txt License line or Link header)not observed
Answers with an x402 payment offer (lower bound: only the homepage is probed)not observed
Answers HTTP 402 Payment Required (lower bound: only the homepage is probed)not observed
Sends noai / noimageai directivesnot observed
Refused our fetcher (403 / challenge)no

robots.txt versions

FromThroughStateVersion
2026-10-272026-10-27ok 2000563ce67fbc4
2026-10-262026-10-26absent 404–

Timeline of changes

DateWhat changed
2026-10-27robots.txt fetch: absent → ok
2026-10-27now blocks Amazonbot (was allow)
2026-10-27now blocks Amzn-User (was allow)
2026-10-27now blocks anthropic-ai (was allow)
2026-10-27now blocks Applebot-Extended (was allow)
2026-10-27now blocks atlassian-bot (was allow)
2026-10-27now blocks Bytespider (was allow)
2026-10-27now blocks CCBot (was allow)
2026-10-27now blocks ChatGPT-User (was allow)
2026-10-27now blocks Claude-User (was allow)
2026-10-27now blocks Claude-Web (was allow)
2026-10-27now blocks ClaudeBot (was allow)
2026-10-27now blocks cohere-ai (was allow)
2026-10-27now blocks Cotoyogi (was allow)
2026-10-27now blocks Diffbot (was allow)
2026-10-27now blocks FirecrawlAgent (was allow)
2026-10-27now blocks Google-Agent (was allow)
2026-10-27now blocks Google-CloudVertexBot (was allow)
2026-10-27now blocks Google-Extended (was allow)
2026-10-27now blocks Google-NotebookLM (was allow)
2026-10-27now blocks GoogleOther (was allow)
2026-10-27now blocks GPTBot (was allow)
2026-10-27now blocks ICC-Crawler (was allow)
2026-10-27now blocks Kimi-User (was allow)
2026-10-27now blocks KimiBot (was allow)
2026-10-27now blocks Meta-ExternalAgent (was allow)
2026-10-27now blocks meta-externalfetcher (was allow)
2026-10-27now blocks MistralAI-Training (was allow)
2026-10-27now blocks MistralAI-User (was allow)
2026-10-27now blocks omgili (was allow)
2026-10-27now blocks Perplexity-User (was allow)
2026-10-27now blocks PetalBot (was allow)
2026-10-27now blocks QualifiedBot (was allow)
2026-10-27now blocks SemrushBot-SWA (was allow)
2026-10-27now blocks WARDBot (was allow)
2026-10-27Content-Signal lines changed

Reconstructed history (Common Crawl)

From Common Crawl's robots.txt captures: what CCBot was served, one crawl per quarter. A separate series from the daily observations above; a 403 here means Common Crawl was refused, not this ledger.

CrawlHostStateGPTBotOAI-SearchBotChatGPT-UserClaudeBotClaude-SearchBotClaude-UserPerplexityBot
2026-09-21 CC-MAIN-2026-39www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows
2024-09-16 CC-MAIN-2024-38www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows
2023-10-02 CC-MAIN-2023-40www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows
2022-10-03 CC-MAIN-2022-40www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows
2021-09-27 CC-MAIN-2021-39www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows
2020-09-28 CC-MAIN-2020-40www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows
2019-09-23 CC-MAIN-2019-39www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows
2018-09-24 CC-MAIN-2018-39www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows
2017-09-25 CC-MAIN-2017-39www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows
2016-09-05 CC-MAIN-2016-36www.ptt.ccabsentallowsallowsunknownallowsallowsunknownallows

Evidence

Every daily observation of ptt.cc is a leaf in that day's Merkle tree. Proof of the robots.txt line for 2026-10-26: audit path (JSON), day root and OpenTimestamps proof (complete (bitcoin block 973294)).

API: https://infrarabbit.com/crawlers/api/v1/policy/ptt.cc