What it does
Diffbot is Diffbot's training crawler. Content is copied into datasets used to train foundation models. Blocking costs you nothing in traffic today; allowing is a donation of your content to model weights with no citation or referral in return.
Commercial extraction/Knowledge-Graph crawler; fetches on behalf of paying customers and has stated it does not treat robots.txt as binding for customer-directed fetches. Docs deep-link 404'd this pass — treat as checked.
Full UA: not captured in our July 2026 roster review — match log hits on the token Diffbot (case-insensitive substring) and verify by IP before acting.
How to verify a hit is really Diffbot
Verification method (July 2026): none documented
User-agent strings are freely spoofed, so a UA match alone proves nothing. Confirm the source IP belongs to Diffbot — published IP-range JSON where available, otherwise RDAP/rDNS on the IP. Full method: verify by IP.
Allow or block in robots.txt
Match the exact token Diffbot in robots.txt:
# Block Diffbot site-wide
User-agent: Diffbot
Disallow: /# Explicitly allow Diffbot
User-agent: Diffbot
Allow: /For the allow-search-block-training combined pattern (and the Allow-directive gotcha that silently kills carve-outs), see the robots.txt guide.
Vendor documentation: https://docs.diffbot.com/
Frequently asked questions
What is Diffbot?
Diffbot is Diffbot's training crawler. Content is copied into datasets used to train foundation models. Blocking costs you nothing in traffic today; allowing is a donation of your content to model weights with no citation or referral in return.
Does Diffbot respect robots.txt?
No — Diffbot does not treat robots.txt as binding. Blocking it requires WAF or IP-level rules.
How do I block Diffbot?
robots.txt cannot stop Diffbot; block it with WAF or IP-level firewall rules instead.