StealthBypass vs Undetectable AI (2026)
The short verdict: choose Undetectable AI for high monthly volume and stronger words-per-dollar, especially on annual billing. Choose StealthBypass for occasional use, a no-card recurring free tier, or a one-off pack without a subscription. This page lays out the current prices and limits behind that answer. We have not run a controlled bypass-rate test, so you will not find pass-rate percentages here.
Comparing more than these two? See the Humanizer vs Undetectable AI vs StealthWriter comparison for the four-way price, free-tier and word-limit table.
Where these numbers come from. StealthBypass plan prices and limits are read directly from our own billing configuration, so they cannot drift out of date. Undetectable AI's figures were taken from their pricing page and official trial instructions on August 27, 2026 — check them yourself before deciding, since they can change at any time.
What both tools do
Both are AI humanizers. They take text generated by ChatGPT, Claude, Gemini, or any other model and rewrite it so it reads less like machine output — varying sentence length, loosening formulaic transitions, and shifting vocabulary away from the most predictable choices. Both also include an AI detector so you can score the result before you use it.
The meaningful differences are in how they package that: what a plan costs, how many words you get, and whether you have to subscribe at all.
Pricing and word limits
This is the comparison that actually decides it for most people. Undetectable AI prices by monthly word pool; StealthBypass does too, with an additional per-run ceiling.
| Plan | StealthBypass | Undetectable AI |
|---|---|---|
| Free | 3 runs/month, 300 words per run, 900 words/month — resets monthly | 250 words, one time |
| Entry paid plan | $4.99/mo — 5,000 words/month | $9.99/mo, or $5.00/mo billed annually ($60/year) — 10,000 words/month |
| Mid plan | $9.99/mo — 10,000 words/month | $19.00/mo, or $9.50/mo billed annually ($114/year) — 20,000 words/month |
| Top plan | $19.99/mo — 20,000 words/month | $42.50/mo, or $21.25/mo billed annually ($255/year) — 50,000 words/month |
| Buy without subscribing | $1.99 / $12.99 humanisation packs | Standard consumer plans are subscriptions |
| Month-to-month billing | Yes, at the prices above | Yes, but the advertised rates are the annual ones |
Read that table honestly and Undetectable AI gives you more words per dollar at every paid tier. If your bottleneck is monthly volume — you are humanizing constantly and want the largest pool for the money — they are the better buy, and we would rather tell you that than pretend otherwise.
Feature differences that are actually verifiable
| Feature | StealthBypass | Undetectable AI |
|---|---|---|
| Built-in AI detector | Every plan, including free | Unlimited on every plan |
| Recurring free tier | Resets monthly, no card | One-time 250-word trial |
| Per-run word ceiling | 300–2,000 by plan | Not published as a separate limit |
| Readability / output modes | Writing styles on paid plans | Named reading levels |
Rows we removed from this table in July 2026: language counts, processing-speed comparisons, bulk-document support, and API availability. Each was stated here as fact with nothing backing it — including the claims about our own product, which is why they are gone rather than restated more carefully.
Why there are no bypass percentages on this page
This page used to carry a table of per-detector pass rates for both tools, introduced with a line about running fifty ChatGPT-generated essays through each humanizer. That test was never run and the numbers were not real. They have been removed rather than adjusted.
A bypass rate is only meaningful with a fixed corpus, a named detector version, a stated pass threshold, and a date — and even then it decays, because detectors update their models continuously and without announcement. A tool advertising “99% bypass” is quoting a number that either was never measured or has already expired. If we run a study we can stand behind, we will publish the method alongside the result.
Which one should you pick?
Most words per dollar — especially if you commit annually for the advertised rate.
A monthly-resetting free tier and a $1.99 pack beat a 250-word trial and a monthly plan.
The most useful thing you can do is run the same paragraph through both free options and compare the output yourself. That takes five minutes and tells you more about which one suits your writing than any comparison table — including this one.
Want more than a two-tool comparison? See the Undetectable AI alternatives guide for other pricing shapes and workflows, or compare our current limits on the StealthBypass pricing page.
Try StealthBypass free — 3 runs a month, no card →