comparison
Siftfy vs Akismet
Updated May 12, 2026
Both classify spam. The differences are in the output format (calibrated probability vs label), the integration story (single REST endpoint vs WordPress-first), and the pricing model. Pick the one that fits your stack.
At a glance
| Siftfy | Akismet | |
|---|---|---|
| Output | Calibrated probability (0–1) | Binary string "true" / "false" from comment-check |
| Free tier | 10,000 requests / month, no credit card | Personal "name your price" (incl. $0) for personal sites; commercial use requires a paid plan |
| Paid pricing | $9 / mo + $0.0001 / req past 1M | Pro $9.95/mo (yearly): 500 calls, 1 site → Business $49.95/mo: 5,000 calls, unlimited sites |
| Per-minute cap (free) | 60 / minute | Not publicly documented |
| Per-minute cap (paid) | 600 / minute, burst-tolerant | Not publicly documented |
| Latency (p99) | < 10ms, CPU only | Not publicly documented |
| Accuracy claim | 99.4% on a public spam test set | 99.99% (Akismet's own marketing copy on akismet.com) |
| Language support | Primarily English; non-English degrades | ISO 639-1 codes via blog_lang; per-language algorithm performance not documented |
| Self-hostable | No (managed only; dedicated on request) | No — managed cloud service only, API key required |
| Stores request bodies | No — metadata only | Yes — submitted content is sent to Automattic and informs the spam model |
| Auth model | Per-key API tokens, revocable in dashboard | Per-account API key |
| Official SDKs | Python (PyPI: siftfy) | First-party WordPress plugin; OpenAPI spec for codegen in any language |
Akismet figures captured 2026-05-10 from akismet.com/pricing and akismet.com/developers. If you spot something out of date, email hi@siftfy.io and we'll fix it.
Where Akismet genuinely beats Siftfy
Akismet has been around since 2005 and is the default for WordPress comment moderation. The honest tradeoffs:
- WordPress / CMS coverage. Akismet ships a first-party WordPress plugin used by millions of sites. Siftfy is REST + Python SDK only — a plugin is on us to write.
- Crowdsourced signal at scale. Years of spam submissions from Automattic's network feed Akismet's model. Our corpus is smaller and English-leaning by comparison.
- Free for personal blogs. Akismet's "Personal" tier is name-your-price, including $0 for non-commercial use. Siftfy's free tier is 10K req/mo regardless of use, so for a tiny personal blog Akismet's free option is hard to beat.
When Siftfy is the right call
- You want a calibrated probability (0–1) rather than a binary "true"/"false" label, so you can pick a threshold per use case (help-desk vs marketplace).
- You're integrating from code, not a CMS — one REST POST, one response, no plugins or webhook dance.
- You need predictable latency in the same datacenter as your app — sub-10ms p99 from the same region, no async queue.
- You want pay-as-you-go pricing without per-site or per-call tiers (Akismet's Pro tier caps at 500 calls / 1 site).
10,000 requests / month free, no credit card. Read the API docs, pricing, or why on-page anti-spam plugins slow down WordPress.