StealthGPT and StealthWriter have similar names and do a similar job. Both are AI humanizers: you paste in text written by ChatGPT or another AI model, and the tool rewrites it so it reads more like human writing and, the vendors say, passes AI detectors such as Turnitin, GPTZero and Originality.ai. Both include an AI detector to check the result. This review compares them from their own pricing pages, checked on 27 October 2026. I have not run either tool against a detector myself, so detection rates are not something I can vouch for.
Before you use an AI humanizer
AI detectors and humanizers keep changing, and a bypass that works today may fail after the next detector update. Detectors also produce false positives on genuinely human writing. If you’re a student, using a humanizer to hand in AI-written work as your own is likely to break your university’s rules even if no detector flags it. The more defensible uses are polishing your own drafts and making AI-assisted marketing or SEO text read naturally where AI use is allowed.
StealthGPT overview
StealthGPT sells three plans, each built around a monthly word allowance:
- Pro, $29.99 a month: 50,000 words a month, 1,000 words per request, .doc and .txt upload.
- Max, $49.99 a month: 200,000 words, 2,000 words per request, PDF and image upload, 3 team seats.
- Enterprise, $179.99 a month: 1,000,000+ words, 10,000+ words per request, 5 seats, API, custom fine-tuned models and a dedicated support channel.
Every plan includes the AI humanizer, AI detector, history, in-text citations, Stealth Insights, 100+ languages, an iOS app, a Chrome extension and MCP access for using it inside Claude, Cursor and similar tools. An add-on called Samurai is offered at checkout. StealthGPT’s page says its newest model beats Pangram and other major detectors and that it has 1.5 million active users.
StealthWriter overview
StealthWriter limits usage per day rather than per month, and it has a free plan:
- Free, $0: 10 humanizations and 10 AI scans a day, 1,000 words per input, Ghost 5.2 Mini model.
- Starter, $20 a month: 50 humanizations and 50 scans a day, 5,000 words per input, Ghost 5.2 Pro and Legacy models.
- Plus, $50 a month: 150 a day, fastest response times, priority support.
- Pro, $100 a month: 350 a day.
- Business, $200 a month: 800 a day, priority team support.
Every plan, including Free, includes the humanizer, the AI detector (V1 and V2) and an AI deep scan. Yearly billing saves 17%.
AI detectors and bypass claims
Both tools say they bypass AI detectors. StealthGPT’s headline is that it beats every AI detector, with Pangram named specifically. StealthWriter is quieter on its pricing page and talks about natural, human-like output. Neither publishes an independent test, and I could not check the claims. If a specific detector matters to you (for example the one your client or publisher uses), run your own text through that detector after humanizing, and read the output closely for changes in meaning.
How to test the output with GPTZero, Originality and other detectors
Because neither vendor publishes independent results, the only test that means anything is your own. A simple approach works:
- Take three pieces of AI text that are typical of your work, around 500 words each.
- Run each through the free StealthWriter plan and, if you’re willing to pay for a month, StealthGPT Pro.
- Check each output in the detector you actually care about (GPTZero, Originality.ai, Turnitin through your institution, or another), and note the AI score.
- Read every sentence of the output against the original. Look for changed facts, odd word choices and lost meaning.
A tool that gets a good detector score but makes the writing worse is not a win. In my view it is often quicker right now to rewrite the flagged sections of AI text yourself, which also keeps your own voice as a writer in the piece.
Pricing compared
| Tier | StealthGPT | StealthWriter |
|---|---|---|
| Free | No free plan listed | 10 humanizations a day, 1,000 words per input |
| Entry | Pro $29.99/month: 50,000 words a month | Starter $20/month: 50 humanizations a day, 5,000 words per input |
| Middle | Max $49.99/month: 200,000 words, 3 seats | Plus $50/month: 150 a day |
| Heavy use | Enterprise $179.99/month: 1,000,000+ words, API | Pro $100/month: 350 a day; Business $200/month: 800 a day |
The two limit usage so differently that the better value depends on how you work. StealthWriter’s Starter allows up to 50 inputs of up to 5,000 words every day, which is a lot of text if you use it daily. StealthGPT’s monthly word pool suits people who work in bursts, such as a big batch of documents at the end of the month, because unused daily allowance on StealthWriter doesn’t carry over.
Ease of use when you humanize text
Both tools use the same paste, humanize and check flow. StealthGPT has more ways in (iOS app, Chrome extension and MCP) and more extras (citations, Stealth Insights, file upload, team seats). StealthWriter lets you choose between its Ghost models on paid plans and includes a deep scan in its detector, but lists fewer extras overall.
Pros and cons
StealthGPT
- Pro: large monthly word pools and long inputs on higher plans.
- Pro: MCP access, iOS app and team seats.
- Con: no free plan listed, so you pay to try it.
- Con: API only on the $179.99 Enterprise plan.
StealthWriter
- Pro: a free plan with 10 humanizations a day.
- Pro: 5,000 words per input from the $20 plan.
- Con: daily limits don’t roll over.
- Con: fewer extra tools than StealthGPT.
Which undetectable AI tool should you pick?
I would start with StealthWriter’s free plan, simply because you can judge the output on your own text without paying. If the Ghost models suit your writing and you humanize regularly, Starter at $20 a month is reasonable value. I would pick StealthGPT if you need to process large documents, share an account with a couple of colleagues or use humanizing inside AI tools through MCP.
Alternative tools
- Undetectable AI: word-based plans from $9.99 a month with a refund if output is flagged, according to its pricing page.
- Rephrasy: yearly plans, a 24 hour pass and a lifetime deal.
- WriteHuman: per request plans with a small free allowance.
