AI Undetect vs StealthWriter

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

Cheaper paid plan: AI Undetect — $5/mo vs $20/mo for StealthWriter
Free plan: Both have one
Public API: AI Undetect has one; not confirmed by us for StealthWriter
Higher Trust score: StealthWriter — 87 vs 72 for AI Undetect
Best fit: AI Undetect: SEO and affiliate writers reworking AI drafts before publishing · StealthWriter: Editing model-drafted marketing copy so it reads less mechanically

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

AI UndetectRewrites AI-drafted text to read as human and pass detector checks, with a built-in multi-detector scan

StealthWriterRewrites AI-written text to read as human and scores it against detectors in the same pass

Side by side

Fact	AI Undetect	StealthWriter
Category	AI Detection & Humanizers	AI Detection & Humanizers
Pricing model	Freemium	Freemium
Starts at	$5/mo	$20/mo
Public API	Yes	Not confirmed
Trust score	72 / 100	87 / 100
Platforms	Web, API	Web
Company	—	AiVantage LLC
Launched	—	2023
Last verified	Oct 15, 2026	Oct 15, 2026

What our research says

AI Undetect

It bundles rewriting and detector checks into one loop, which is the workflow people actually follow, and entry pricing is low. The catch is the category itself: detection engines retrain constantly, so passing today proves nothing about next month, and using it on academic work can breach integrity policies.

Pros

Free allowance to test output quality before paying
Detector panel shows results across multiple engines at once
Low entry price on annual billing
Rewrite API is documented for integration work

Cons

Effectiveness is a moving target as detectors retrain
The company behind the site is not identified anywhere on it
Word caps on lower tiers are easy to exhaust

StealthWriter

Pairing the rewriter with its own detector in one screen is the sensible design choice here — you can see the before and after score instead of pasting into a third tool to find out. The tiering is honest about what you are buying: daily rewrite count and input length, nothing hidden. Everything else about this category applies, though: detector scores are not a guarantee, the rewrite flattens voice and sometimes meaning, and using it on assessed work is a disciplinary matter regardless of what the score says.

Pros

Built-in detector scores text before and after the rewrite in the same interface
Free tier is a standing 10 rewrites a day, not a one-off trial
Every paid tier raises input length to 5,000 words, so tiers differ only by volume
Named US operator with published phone and email support hours
Changelog actively maintained, indicating ongoing development

Cons

Detector evasion degrades as detectors update — today's score is not a durable result
Rewriting flattens voice and can quietly alter facts or technical terms
$400/month top tier is steep for a single-function tool, and there is no API to justify it
Free tier's 1,000-word input cap excludes most real articles

Which one fits

Choose AI Undetect if you need

SEO and affiliate writers reworking AI drafts before publishing
Non-native English speakers smoothing machine-assisted prose
Teams that want rewrite plus detector check in one place

Choose StealthWriter if you need

Editing model-drafted marketing copy so it reads less mechanically
Checking a draft's detector score before it goes to a client who screens for AI text
Non-native writers polishing model-assisted drafts for tone