comparison
Siftfy vs CleanTalk
Updated May 12, 2026
Both stop spam, but the integration shape is different. CleanTalk bundles signup, comment, and registration anti-spam across many CMS plugins; Siftfy is one HTTP endpoint you call from wherever you want a spam check. Pick the one that fits where you ship code.
At a glance
| Siftfy | CleanTalk | |
|---|---|---|
| Output | Calibrated probability (0–1) | Binary appears (0/1) plus spam_rate (0–1) and a frequency count from the crowdsourced blacklist |
| Free tier | 10,000 requests / month, no credit card | 7-day trial at registration, no credit card; no permanent free tier |
| Paid pricing | $9 / mo + $0.0001 / req past 1M | $12/yr for 1 site, $69/yr for 10 sites, $27/mo for unlimited sites — per-site, not per-call |
| Per-minute cap (free) | 60 / minute | Unlimited ("no limits on API calls" per pricing page) |
| Per-minute cap (paid) | 600 / minute, burst-tolerant | Unlimited (per pricing page) |
| Latency (p99) | < 10ms, CPU only | Not publicly documented |
| Accuracy claim | 99.4% on a public spam test set | Not publicly documented as a percentage |
| Language support | Primarily English; non-English degrades | Not specified for the algorithm; documentation localised in English and Russian |
| Self-hostable | No (managed only; dedicated on request) | No — managed cloud only (the crowdsourced blacklist would be moot offline) |
| Stores request bodies | No — metadata only | Yes — submissions feed CleanTalk's crowdsourced spam database that other subscribers query |
| Auth model | Per-key API tokens, revocable in dashboard | Per-account access key (auth_key) |
| Official SDKs | Python (PyPI: siftfy) | First-party plugins for WordPress, Joomla, Drupal, MODX, Bitrix and other PHP-era CMSes |
CleanTalk figures captured 2026-05-10 from cleantalk.org/price-anti-spam and cleantalk.org/help/api-spam-check. If you spot something out of date, email hi@siftfy.io and we'll fix it.
Where CleanTalk genuinely beats Siftfy
The honest tradeoffs:
- Per-site pricing for low-volume sites. $12/year for one website is dramatically cheaper than any paid Siftfy tier if your traffic is small. Siftfy's metered model only wins above the free 10K req/mo line.
- CMS plugin breadth. First-party plugins for WordPress, Joomla, Drupal, MODX, Bitrix, and others mean the install is a checkbox, not a code change. Siftfy is a REST + Python SDK call — you're writing some glue.
- Crowdsourced blacklist. CleanTalk's database is fed by submissions from many subscribed sites, so a known-bad IP that hit another customer is already flagged for you. Useful for IP / email reputation lookups Siftfy doesn't offer.
When Siftfy is the right call
- You're integrating from your own application code (Node, Python, Go, etc.) and want a single endpoint, not a CMS plugin.
- You want a calibrated probability you can threshold per surface, rather than a binary appears flag plus a global crowdsourced reputation score.
- You care about p99 latency in the same datacenter as your app — under 10ms — so the spam check doesn't add a perceptible delay to a form submission.
- You don't want submitted content to flow into a third-party crowdsourced database — Siftfy stores metadata only.
10,000 requests / month free, no credit card. Read the API docs or pricing.