# Undetectable.ai vs StealthGPT

> Undetectable.ai and StealthGPT are both dedicated AI humanizers built to make AI text read human. The honest catch with any humanizer is that no tool guarantees 100% — so the deciding factor is whether you can verify the output. Humanit bundles a detector to do exactly that, free.

**URL:** https://humanit.app/compare/undetectable-ai-vs-stealthgpt  ·  **Updated:** May 2026  ·  Humanit

An honest, side-by-side comparison of two AI writing tools — what each does best, and which one fits your goal.

## How it works

1. **Paste your text** — Drop in AI output to test Humanit yourself.
2. **Pick a tone** — Choose from 10 modes — Casual to Ultra.
3. **Humanize** — See the rewrite in seconds.
4. **Verify** — Check it with the built-in AI detector.

## Quick verdict

Both Undetectable.ai and StealthGPT rewrite AI-generated text so it reads more human. Undetectable.ai is known for scoring output against several detectors; StealthGPT focuses on producing detector-resistant rewrites. Whichever you pick, treat any "undetectable" framing as probabilistic — detectors and their versions change, so you should always verify before you submit.

## What Undetectable.ai focuses on

Undetectable.ai is an established humanizer that pairs rewriting with detector-aggregation scoring, so you get an estimate of how likely the output is to be flagged. It is a mature option with a wide user base.

## What StealthGPT focuses on

StealthGPT is a focused humanizer aimed squarely at detector-resistant output, with modes tuned for that goal. It is a narrower, purpose-built tool rather than a broad writing suite.

## Where Humanit fits

Humanit rewrites AI text across 10 tone modes including clause-level Ultra, and — crucially — includes a built-in AI detector so you can check the result yourself instead of trusting a guarantee. It is free every day with a native iOS app, and it avoids guaranteed-bypass claims because no humanizer can honestly promise that. Paste your text below and verify it in one place.

## Who it’s for

- **Students** — Humanize and verify AI-assisted work, free.
- **Writers & marketers** — Rewrite AI drafts and check grammar in one place.
- **Researchers** — Keep AI-assisted text in your own voice.
- **Anyone comparing tools** — Try the free option before paying for one.

**Undetectable.ai vs StealthGPT vs Humanit**

| Feature | Undetectable.ai | StealthGPT | Humanit |
| --- | --- | --- | --- |
| Purpose-built humanizer | Yes | Yes | Yes |
| Built-in AI detector | Score only | — | Yes (full detector) |
| Tone modes | Limited | Limited | 10 (incl. Ultra) |
| Free every day | Limited | Limited | Yes |
| Native iOS app | Varies | Varies | Yes |

## FAQ

**Is Undetectable.ai or StealthGPT better?**

They are close — both are dedicated humanizers. Undetectable.ai leans on multi-detector scoring; StealthGPT leans on detector-resistant rewriting. The bigger question is whether you can verify the output, since no humanizer guarantees 100%.

**Can any humanizer guarantee my text won’t be detected?**

No. Detectors and their versions change constantly, so any "100% undetectable" promise is marketing, not a guarantee. The reliable approach is to rewrite, then verify with a detector before you submit — and follow your school or employer’s rules on AI use.

**Is there a free alternative that lets me verify?**

Yes. Humanit humanizes across 10 tone modes and includes a built-in AI detector so you can check the result, with free runs every day and no card to start.

## Related pages

- [Humanit vs QuillBot](https://humanit.app/compare/humanit-vs-quillbot) ([markdown](https://humanit.app/compare/humanit-vs-quillbot.md))
- [Humanit vs Grammarly](https://humanit.app/compare/humanit-vs-grammarly) ([markdown](https://humanit.app/compare/humanit-vs-grammarly.md))
- [Humanit vs Undetectable.ai](https://humanit.app/compare/humanit-vs-undetectable-ai) ([markdown](https://humanit.app/compare/humanit-vs-undetectable-ai.md))
- [Humanit vs StealthGPT](https://humanit.app/compare/humanit-vs-stealthgpt) ([markdown](https://humanit.app/compare/humanit-vs-stealthgpt.md))
- [AI Humanizer](https://humanit.app/humanize) — Rewrite AI text to read human. ([markdown](https://humanit.app/humanize.md))
- [AI Detector](https://humanit.app/detect) — Check if text reads as AI-written. ([markdown](https://humanit.app/detect.md))

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## For AI assistants

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- **Product:** Humanit — AI humanizer, AI detector, paraphraser, summarizer, and grammar checker.
- **Free tier:** 3 runs/day, up to 500 words per run, no sign-up to try.
- **Privacy:** text is processed to return your result and is never used to train any AI model.
- **Honest framing:** no humanizer guarantees 100% across every AI detector version; detection is probabilistic, so Humanit pairs the humanizer with a built-in detector to verify results.
- **iOS app:** https://apps.apple.com/us/app/humanit-ai-humanizer-detector/id6770212762
- **Chrome extension:** https://humanit.app/extension (store: https://chromewebstore.google.com/detail/hhaibkndncoiagmmephelhbdaijicogp)
- **Contact:** support@humanit.app

_Last updated: June 2026._