Undetectable AI vs WriteHuman
Undetectable AI and WriteHuman are the two best-known AI humanizers, and both are honest about the same caveat: no tool guarantees a pass on every detector. WriteHuman led the October 2026 HumanizerBench cycle at 74.89, fourth straight month at number one, and charges per request: free tier with no signup, Basic $20/month (80 humanizations), Pro $29/month (200), Ultra $59/month unlimited, plus a REST API from $29/month (observed October 2026). Undetectable AI meters by word: free 250-word trial, Starter 10,000 words at $9.99/month ($5/month annual), Pro 20,000 at $19/month ($9.50 annual), Growth 35,000 at $31/month, with a built-in detector and API access (observed September 2026). Independent tests show real variance: WriteHuman scored 99.5% on GPTZero but HumanizerPro's test found it altered facts, while Undetectable AI's rewrites still landed 71-88% AI on Originality.ai. If you humanize in small batches and want a free no-signup test, WriteHuman's metering fits; if you humanize by volume, Undetectable AI's word tiers fit. Either way, verify facts after every rewrite. We did not hands-on test either product, so no quality winner is declared.
| Decision point | Undetectable AI | WriteHuman |
|---|---|---|
| Best suited to | Content teams softening stiff AI-drafted marketing copy before publishing | Writers who humanize in batches and want a free no-signup test first |
| Plans and cost | Free 250-word trial. Starter 10,000 words $9.99/month ($5/month on annual billing); Pro 20,000 words $19/month ($9.50/month annual); Growth 35,000 words $31/month; Business custom. Observed September-October 2026. | Free tier (no signup). Basic $20/month, Pro $29/month, Ultra $59/month. API Standard $29/month (125,000 words), Premium from $69/month. Observed October 2026. |
| Limitations | Independent 2026 tests show it does not reliably beat detectors: Originality.ai still flagged its rewrites at 71-88% AI and GPTZero was near a coin flip, so always test your own content. Multiple user | Humanizers alter meaning: an independent 2026 review found dropped facts and an invented claim in WriteHuman output, so every rewrite needs a fact check. It is metered per request with per-request wor |
Use the same input
A marketer needs to soften AI-drafted copy and must choose between per-request and per-word humanizer pricing.
What a successful result must preserve
The tool must match the real job (batch vs volume humanizing) and the budget must be based on current list pricing, not directory memory.
Evidence and test status
Specification comparison based on published pricing and feature pages plus independent benchmark tests, checked October 2026. We did not run a hands-on test on either tool; no quality winner is declared.
- Undetectable AI — Official website ↗ (reviewed 2026-10-24)
- WriteHuman — WriteHuman AI Humanizer Tool: Humanize AI Text ↗, Pricing - AI Humanizer Plans & Pricing | WriteHuman ↗