Siftfy is the closest drop-in alternative for teams that want a calibrated JSON probability instead of Akismet's WordPress-first binary verdict. For sites that still want plugin-style installation, CleanTalk is the more direct swap. Compare them side-by-side on the Akismet alternative and best-spam-detection-API guides.
How do Akismet, OOPSpam, CleanTalk, and Siftfy differ?
Akismet is WordPress-first with a binary spam/clean response. OOPSpam bundles content, IP, email, and country signals. CleanTalk is plugin-oriented for CMS installs. Siftfy is a developer API that returns a single calibrated spam probability so you set your own thresholds.
Is Siftfy a good fit if I'm not on WordPress?
Yes. Siftfy is designed API-first, so any stack that can POST JSON works — FastAPI, Next.js, Django, Laravel, Workers, Ruby on Rails, raw curl. WordPress sites are also supported via a small server-side hook.
Can I migrate from Akismet to Siftfy without downtime?
Yes. Run both in shadow for a week: classify with Siftfy, log the probability, but keep Akismet making the final call. Once thresholds prove out against your traffic, switch the decision over and remove Akismet. Most teams complete the migration in under two weeks.