What StealthGPT is
StealthGPT is unusual in this category because it does two distinct jobs: it will generate new content from a prompt, and separately it will take existing AI-written text and rewrite it to read less like AI output. Most tools in this space only do the second job. StealthGPT markets both functions aggressively around the word “undetectable”, positioning itself as a way to produce or launder AI writing that clears detection.
That combination (write it, then also disguise that it was written) is the core of its pitch, and it is aimed at a different use case than most of the tools it competes with: someone who wants AI to do the original writing, not someone polishing a draft they wrote themselves.
Where NeverPrompted is built differently
NeverPrompted has no generation feature, on purpose. It doesn’t write anything for you. It takes text you already produced and helps you reduce the patterns that make your own writing read as AI-generated, or checks it for a statistical watermark, and that’s the whole feature set. If your starting point is a blank page and a prompt, NeverPrompted isn’t the tool for that step; it’s the tool for the step after you’ve written something and want to know how it reads.
The processing happens entirely on your device, nothing is uploaded to check or rewrite a document on any plan, and every suggested edit shows up as a diff against your original sentence so you decide, line by line, what actually changes. That review step exists because the goal is writing that is still recognizably yours, just without the tells, not a replacement paragraph you didn’t choose.
What neither of us can promise
StealthGPT’s marketing centers on “undetectable” as a property of its output, for both the writing it generates and the writing it rewrites. That claim runs into the same wall every tool in this category hits: an AI provenance watermark is a statistical signature applied by the model that generated the original text, and it can only be reliably checked by whoever holds that model vendor’s detection key. No rewriting tool downstream, however aggressive, has access to that key, so no rewriting tool can honestly certify that a watermark has been defeated.
NeverPrompted states this plainly rather than around it: we can reduce the human-legible AI tells in text and tell you what we found (or didn’t find) under the watermark keys we hold, but we cannot guarantee a document will evade an undisclosed vendor’s mark, and neither can StealthGPT, whatever its marketing says. If a document needs to survive genuine scrutiny, that limit is worth knowing before you rely on any tool, ours included.
Wherever this page describes a result: a detected mark is not proof of authorship, and an absent mark is not proof of human authorship. NeverPrompted's on-device rewrite can reduce detectable evidence but cannot guarantee defeating a vendor's undisclosed watermark, on any tier.