StealthBypass vs Undetectable AI (2026)

Undetectable AI is one of the best-known AI humanizers, and on raw words-per-dollar it is hard to beat. This page lays out what each tool actually costs and includes, so you can pick on facts rather than on whose comparison page you landed on first. We have not run a controlled bypass-rate test between the two, so you will not find pass-rate percentages here.

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 StealthBypass plan prices and limits are read directly from our own billing configuration, so they cannot drift out of date.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 in July 2026 — check it yourself before deciding, since they can change it 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.

PlanStealthBypassUndetectable AI
Free3 runs/day, 500 words per run, 2,500 words/month — resets daily250 words, one time
Entry paid plan$4.99/mo — 5,000 words/month$5.00/mo billed annually — 10,000 words/month
Mid plan$9.99/mo — 10,000 words/month$9.50/mo billed annually — 20,000 words/month
Top plan$19.99/mo — 20,000 words/month$21.25/mo — 50,000 words/month
Buy without subscribing $1.99 / $4.99 credit packs Subscription only
Month-to-month billing Yes, at the prices aboveYes, 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

FeatureStealthBypassUndetectable AI
Built-in AI detector Every plan, including free Unlimited on every plan
Recurring free tier Resets daily, no card One-time 250-word trial
Per-run word ceiling5002,000 by planNot published as a separate limit
Readability / output modesWriting styles on paid plans Named reading levels
Unused credits roll over Lite 10, Pro 25Not published

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?

Pick Undetectable AI if
You humanize at volume, every month

Most words per dollar — especially if you commit annually for the advertised rate.

Pick StealthBypass if
You have a handful of documents

A daily-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.

Try StealthBypass free — 3 runs a day, no card →

Frequently Asked Questions

It depends on volume, and Undetectable AI wins at the top end. Their 10,000-word plan is $5.00/month billed annually ($60.00/year), or $9.99 if you pay month-to-month — both checked July 2026. StealthBypass Lite is $4.99/month for 5,000 words and Pro is $9.99/month for 10,000. Being precise about that: at $9.99 month-to-month for 10,000 words they are priced identically to our Pro tier, so we are not the cheaper month-to-month option at that level — an earlier version of this page implied we were. We are cheaper at the entry tier, and cheaper still if a one-off credit pack covers what you need instead of any subscription. If you write a lot every month, or you are happy to commit to a year, Undetectable AI gives you more words per dollar.
Yes. Undetectable AI lists unlimited AI detection on every subscription tier (checked July 2026), and StealthBypass returns a detector score on your humanized output on every plan including free. This is not a difference between the two tools — an earlier version of this page claimed it was, which was wrong.
Both offer something free, but they work differently. Undetectable AI's free trial is a one-time 250 words. StealthBypass's free plan gives you 3 humanizations a day of up to 500 words each, and it resets daily rather than running out permanently — no card required either way.
We do not publish a number for this, and we would treat anyone who does with caution. A credible bypass rate needs a fixed corpus, a documented detector version, and a repeatable method — detectors change their models without notice, so a figure measured once stops being true quickly. We have not run that study, so there is no percentage on this page. The honest answer is that no humanizer can guarantee a result against a detector it does not control.
It rewrites at the sentence level rather than swapping synonyms, so arguments, citations, and structure are meant to survive the pass. That said, any rewrite can drift — read the output before you submit it. The detector score tells you how the text scans, not whether it still says what you meant.
This is where StealthBypass is genuinely the cheaper option. You can buy a Quick Pass for $1.99 (5 humanizations) or a Deadline Pack for $4.99 (20 humanizations, 60 days) without starting a subscription. Undetectable AI is subscription-based, so a single deadline costs you a monthly plan.
The median completed run takes about 2.4 seconds, measured from our own usage logs rather than estimated. We do not have comparable timing data for Undetectable AI, so this page does not claim one is faster than the other.

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