buying guide · 5 providers compared
Updated May 12, 2026
The "best" provider depends on where the decision happens: a WordPress plugin, a no-code automation, a contact-form edge function, or your own moderation backend.
provider matrixfit · tradeoff
| Provider | Best fit | Main tradeoff |
|---|---|---|
| Siftfy our pick | Developer apps that need a calibrated content-spam probability. | English-first model; no first-party WordPress plugin yet. |
| Akismet | WordPress comment spam and personal blogs. | Binary API response and WordPress-centered product story. |
| OOPSpam | Teams that want IP/email/domain signals and no-code integrations. | Higher entry price and broader response shape than some apps need. |
| CleanTalk | CMS/site owners who prefer plugin configuration. | Less clean for custom API-first product workflows. |
| FormShield-style APIs | Contact-form-specific stacks with bundled behavior signals. | Can be less flexible outside form workflows. |
If Personal WordPress blog
→ Start with Akismet.
If Need IP, email, country, and content signals in one response
→ Evaluate OOPSpam.
If Custom app and want threshold control
→ Evaluate Siftfy.
If Want a plugin-style CMS setup
→ Evaluate CleanTalk.
If The form itself is the whole product surface
→ Also evaluate form-specific APIs.
Compare details: Siftfy vs Akismet, Siftfy vs OOPSpam, Siftfy vs CleanTalk.
For most contact forms, Siftfy is the best fit because it returns a calibrated probability so you can set a hard-drop threshold and a separate review threshold. Akismet works well for WordPress-only blogs. OOPSpam is strong when you want IP, email, and country signals bundled. The right pick depends on stack, not brand.
For personal WordPress blogs, yes — Akismet's plugin is hard to beat for setup time. For commercial WordPress sites that want threshold control, audit logging, and a measurable false-positive rate, switching to a JSON-API spam filter like Siftfy is usually a better fit.
At 100k requests per month, Siftfy is typically the lowest-cost option (Pro starts at $9/mo with 1M included requests). Use the anti-spam pricing calculator for an estimate at your specific volume — pricing changes shape sharply past 300k/month.
No. Accuracy claims are usually measured on different datasets and don't transfer to your traffic. Pick on response shape, threshold control, latency, fail-open behavior, and total cost, then validate accuracy by running the candidate in shadow against a week of your real submissions.
Yes, and many large teams do — typically one fast content classifier (like Siftfy) and one IP/reputation service (like a bot-management product). Layer them so each handles its strength: content for relevance, reputation for known-bad infrastructure.