| Undetectable AI | Phrasly AI | |
|---|---|---|
| Starting price | $9.99/mo | $12.99/mo |
| Free tier | 250 words | 300 words |
| Bundled detector | Yes | Yes |
| Founded | 2022 | 2023 |
| Best for | Teams that want one tool to both check and rewrite content across multiple AI models. | Users who want the current highest-ranked general-purpose humanizer without extra bundled features. |
Price: Undetectable AI is cheaper to start, at $9.99/mo vs $12.99/mo.
Undetectable AI: $9.99/mo for the entry tier; higher tiers scale by word volume.
Phrasly AI: $12.99/mo for unlimited humanization after a 300-word free allowance.
Free tier: Phrasly AI offers a more generous free tier (300 words).
If you just want to test either tool before paying, Phrasly AI's 300-word allowance gives you more room to evaluate quality.
Detection performance
Undetectable AI: Frequently cited as a top-tier performer against GPTZero and Originality.ai, though results vary by source text length and topic.
Phrasly AI: The tool most frequently named 'best overall' in third-party 2026 testing roundups, ahead of Undetectable AI and StealthGPT.
AI detector included: Undetectable AI bundles a built-in detector; both both include one.
Strengths at a glance
Undetectable AI
- Runs output against multiple detector models before returning it
- Supports long-document processing without manual chunking
- Adjustable readability and purpose settings (story, essay, article, email)
Phrasly AI
- Consistently ranked #1 across several independent 2026 comparison tests
- Clean, minimal interface — paste, humanize, done
- Built-in detector shows a live score before you export
Our verdict
Choose Undetectable AI if: teams that want one tool to both check and rewrite content across multiple ai models. Choose Phrasly AI if: users who want the current highest-ranked general-purpose humanizer without extra bundled features.