Undetectable AI Review 2026

Undetectable AI is one of the best-known AI humanizers: paste text from ChatGPT, Claude or Gemini, and it rewrites the draft so it reads less like a model and scores lower on AI detectors. The pricing is simple, the promise is not. You buy a monthly word allowance, while the vendor's marketing says the output scores as human on every major detector, a claim that independent tests do not agree on.

Toolradar data: on Undetectable AI's Toolradar profile, the software directory we run, it is listed as an alternative to 2 other tools, joint #115 of the 304 tools in its peer group. In that group 42% of tools have a free plan, while Undetectable AI offers only a short trial (snapshot of November 3, 2026).

Below we cover what each plan includes, what a semester, a year and a heavy month cost, what the refund and cancellation terms say, and how WriteHuman, GPTHuman, StealthWriter and Grammarly price the same work. Every price was read on the vendor's own pages on November 4, 2026.

Undetectable AI is a web app and Chrome extension built around two tools: an AI humanizer that rewrites machine-written text, and an AI detector that scores text before you submit it. Around them sit a paraphraser, an essay writer, a Human Auto Typer for Google Docs, an AI job applier and detectors for images, audio, video and fake documents.

The humanizer is built for English first. Its help center lists 55 language codes with secondary support, from Afrikaans to Vietnamese, so anyone humanizing in another language is relying on a secondary feature, not the one the marketing is built on. The vendor puts processing at 10 to 30 seconds per document, and the homepage editor accepts up to 5,000 words at a time.

You paste a draft, pick the output settings and get a rewritten version, with the built-in detector showing how the result scores. Every humanized word counts against your monthly allowance, while the detector and the Human Auto Typer are unlimited on all paid plans. That split matters: checking text is free once you subscribe, but every rewrite and every retry spends words.

Retries are a real cost. A test run by a rival humanizer site put the same essay through the tool three times and got three different Turnitin scores, so a careful user may humanize important text twice. On the 10,000-word plan, two passes over a 2,500-word paper use half the month.

The Business tier works differently. It sells bulk credits that do not expire each month, plus redistribution and white-labeling rights, at custom prices agreed by email. That suits agencies and API users rather than individual writers.

Undetectable AI sells four self-serve word plans and a custom Business tier, each available on monthly or yearly billing, at the prices in the table below, as listed on Undetectable AI's pricing page on November 4, 2026. Yearly billing costs half the monthly rate, and the vendor presents it as a 50% sale. That discount is not new: an archived copy of the pricing page from November 2025 already showed the 10,000-word plan at $5 a month on yearly billing under a "Limited Time" label.

Scenario one, a student who needs about 5,000 words a month for a four-month term: four monthly payments on the smallest plan cost $39.96 (our arithmetic), less than the yearly charge for that plan. For anyone who keeps it longer than six months, yearly wins, since six monthly payments already cost $59.94.

Scenario two, a freelancer humanizing 20,000 words a month for a year: the 20,000-word plan costs $114 yearly or $228 on twelve monthly payments. GPTHuman's Starter plan covers 25,000 words a month for $99 a year, and WriteHuman's Basic plan, 80 requests of up to 600 words, costs $144 a year. Per 1,000 words, Undetectable's yearly 10,000-word plan works out to $0.50 and GPTHuman's yearly Starter to $0.33 (our arithmetic).

Scenario three, a heavy month: the 50,000-word card costs $42.50 a month, or $21.25 a month on yearly billing. Beyond the slider's 380,000 words, Business pricing is by quote.

Read the terms before paying. The terms of service say you lose your remaining words the moment you cancel, that only California and New York residents can cancel in the dashboard (everyone else cancels by email), and that credits are refunded only when a submission provably scores under 75% human on a reputable detector, claimed within 30 days. The help page describes the guarantee as a refund of the generation's cost, which is not a promise that your text will pass.

Rival prices come from the WriteHuman pricing, GPTHuman pricing, StealthWriter pricing and Grammarly Pro pricing pages, read the same day. Methodology: list prices in USD from each vendor's own page, totals computed from the printed rates, and bypass results quoted from the published tests linked below; we ran no detection tests ourselves.

Undetectable AI fits writers whose editor or client allows AI drafting but wants text that reads as human: marketers polishing AI copy, freelancers asked for a clean detector score, non-native writers smoothing a draft. The vendor's own ethics page draws that line itself, listing marketing content and drafting as acceptable and cheating in school or getting around a "no use of AI" policy as unacceptable.

Students should be the most cautious buyers. Most schools treat passing off humanized AI text as your own work as an integrity breach, and a lower detector score does not change what the work is. The vendor's own Auto Typer page pitches that tool for creating revision history in Google Docs and avoiding GPTZero writing reports and Draftback, tools built to show how a document was written. Our guide to using AI for essays covers where AI help is usually allowed, and our AI tools for students page lists the study tools that carry no such risk.

Skip it if you mainly want cleaner writing rather than a lower detector score: a grammar and style tool does that job, and Grammarly's free humanizer is a cheaper first step. If your role is checking text rather than rewriting it, compare the detectors in our GPTZero review and Originality.ai review instead.