| QuillBot Humanizer | StealthGPT | |
|---|---|---|
| Starting price | $8.33/mo | $14.99/mo |
| Free tier | 125 words | 0 words |
| Bundled detector | Yes | No |
| Founded | 2017 | 2023 |
| Best for | People who already pay for QuillBot's grammar/paraphrase suite and want a decent bonus feature, not a dedicated bypass tool. | Long-form academic or research writing where sentence-level restructuring matters more than speed. |
Price: QuillBot Humanizer is cheaper to start, at $8.33/mo vs $14.99/mo.
QuillBot Humanizer: $8.33/mo billed annually, $19.95/mo monthly. Free tier: 125 words, 6 uses/day.
StealthGPT: Plans from $14.99/mo; per-word bundles available for one-off use.
Free tier: QuillBot Humanizer offers a more generous free tier (125 words).
If you just want to test either tool before paying, QuillBot Humanizer's 125-word allowance gives you more room to evaluate quality.
Detection performance
QuillBot Humanizer: Consistently ranks behind dedicated humanizers on Turnitin and GPTZero in third-party comparisons because it leans on synonym substitution rather than deep sentence restructuring.
StealthGPT: Positioned and marketed specifically around Turnitin's originality algorithm rather than general-purpose detectors.
AI detector included: QuillBot Humanizer bundles a built-in detector; StealthGPT does not.
Strengths at a glance
QuillBot Humanizer
- Bundled AI detector, grammar checker, and paraphraser in one subscription
- Fast — results in under 5 seconds for short passages
- Color-coded change tracking so you can see exactly what was rewritten
StealthGPT
- Generates and rewrites in one pass, so you can skip a separate AI writer
- Aggressive sentence-level restructuring rather than word substitution
- No word cap on paid plans — good for full-length papers
Our verdict
Choose QuillBot Humanizer if: people who already pay for quillbot's grammar/paraphrase suite and want a decent bonus feature, not a dedicated bypass tool. Choose StealthGPT if: long-form academic or research writing where sentence-level restructuring matters more than speed.