StealthGPT vs Undetectable AI

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors.

The short answer

Free plan: Only Undetectable AI (StealthGPT has paid plans only)
Public API: Both have one
Best fit: StealthGPT: Content operations running bulk rewriting through an API or n8n workflow · Undetectable AI: Marketers cleaning up bulk LLM drafts before publishing
Platforms: StealthGPT: Web, Chrome extension, iOS · Undetectable AI: Web, Chrome extension
Trust score: About even — StealthGPT 86, Undetectable AI 89

From our own records as of each tool's last check. Anything we have not confirmed is left out rather than guessed. How we verify

StealthGPTRewrites AI-generated text to slip past AI detectors

Undetectable AIRewrites machine-written drafts to read human, with detection scoring built in

Side by side

Fact	StealthGPT	Undetectable AI
Category	AI Detection & Humanizers	AI Detection & Humanizers
Pricing model	Paid	Freemium
Starts at	—	$9.99/mo
Public API	Yes	Yes
Trust score	86 / 100	89 / 100
Platforms	Web, API, Chrome extension, iOS	Web, API, Chrome extension
Company	XYZ AI, Inc.	Undetectable Inc.
Launched	2023	2023
Last verified	Oct 22, 2026	Oct 15, 2026

What our research says

StealthGPT

The only thing here that competitors do not match is the developer surface — REST API, MCP server and n8n node — so this is the humanizer you pick if you are automating a content pipeline, not the one you pick to write an essay. Everything it sells is a bet on an arms race the detector vendors are also funding.

Pros

Genuine developer stack — documented API reference plus an MCP server, which rivals lack
Bundled detector lets you check before and after in one place
Chrome extension humanizes directly in any text field
Enterprise tier handles up to 20,000 words per run

Cons

Pricing page is behind a Vercel bot check, so prices cannot be compared without signing up
Daily request caps sit behind plans that market themselves as unlimited
Rewriting reliably flattens nuance and introduces awkward phrasing that needs an editing pass
Positioning around beating Turnitin invites institutional and reputational risk

Undetectable AI

Buy it only if you accept that passing a detector is a moving target: detector vendors retrain constantly, and text that cleared last month can flag next month. As a multi-format detection dashboard it is more defensible than as a bypass tool.

Pros

Detector and rewriter run in one pass, so you see which sentences changed and why
Coverage extends past text into image, voice, video and document classifiers
Browser extension works inside Docs and Gmail rather than a separate tab
Entry tier is genuinely cheap at annual rates

Cons

Rewrites often flatten voice and add filler to break statistical patterns
Detection on short passages is unreliable in both directions
Word quotas drain fast because rejected attempts still consume them
The free trial caps at 250 words, barely enough to judge output quality

Which one fits

Choose StealthGPT if you need

Content operations running bulk rewriting through an API or n8n workflow
Non-native English writers softening obviously templated LLM prose
Agencies that need humanizing inside an existing WordPress or Zapier stack

Choose Undetectable AI if you need

Marketers cleaning up bulk LLM drafts before publishing
Editors wanting a second opinion on submitted copy
Teams screening images and audio for synthetic origin
Non-native writers smoothing register and tone