IWF Hash List

The Internet Watch Foundation's hash list contains hashes of child sexual abuse images and videos that IWF analysts have personally assessed and categorized under UK law, with each hash tagged by severity. It's updated daily and supplied in PhotoDNA, MD5, SHA1 and PDQ formats so you can match with whatever pipeline you run. IWF also supplies a URL blocklist and a keyword list.

Access is through IWF membership, which brings the lists, analyst support, and a hotline relationship for reporting. It's the most heavily curated CSAM hash source available.