AIUndetect Humanizer Review (2026): Pricing, Credits & API
AIUndetect Humanizer review: four processing modes, 20+ languages, credits that roll over on renewal, a separate API product, and plans from US$10 a month.
AIUndetect is a humanizer and AI detector combined, built for marketers, SEO writers, bloggers and students who rewrite AI-assisted drafts in 20-plus languages. Plans run from a free trial up to a Pro tier with no monthly word cap, and a separate API serves developers.
An AIUndetect humanizer review is most useful when it sticks to what you can check yourself: word limits, prices, languages, the detector caps and the API. Those numbers decide which plan fits your work.
What is AIUndetect?
AIUndetect is run by AIundetect LLC, doing business as AI Undetect. Its Terms are governed by the law of the State of Idaho. The site offers one main tool, a combined humanizer and detector, plus a separate API product for developers at a different subdomain.
The homepage itself is the tool, so you land directly on the input box, with pricing, FAQ and blog links further down the same page. A tools subdomain also lists several hundred third-party AI products aimed at students, as a directory of other companies' tools. It's a browsing resource, separate from your AIUndetect account and plan.
You paste a draft or upload a file, pick a processing mode and a language, then run the rewrite. The same screen lets you check the text for AI patterns too, so a first draft, its rewrite and a check all happen without leaving the page.
AIUndetect's FAQ says the service suits marketers, SEO specialists, writers, bloggers, journalists and researchers. It adds that the tool is aimed at people worried about a false AI-content accusation. If that's brought you here, our breakdown of why AI detectors flag non-native writers covers a common cause worth ruling out first.
How AIUndetect's humanizer and detector work
The main tool uses a simple layout: a text box, a word counter, and buttons for Check For AI and Humanize AI.
Four processing modes
Above the text box, AIUndetect offers four modes: Manual, Auto-Perfect, Balance and General. These set how the rewrite handles your draft. The anonymous demo caps input at 250 words; signing in raises that ceiling, and a paid plan raises it further still.
Detector checks with their own daily cap
AIUndetect's detector runs separately from the humanizer and has its own daily usage cap, apart from the word allowance. Basic allows 30 detector checks a day, and Standard and Pro both allow unlimited checks. AIUndetect names several detectors it has built checks for, including Winston AI. Our own look at Winston's detector accuracy is a useful second opinion on any single score.
20-plus languages
A language switcher on the homepage lists more than 20 options. Alongside English, it covers Chinese, Spanish, Portuguese, German, French, Japanese, Korean, Russian, Hindi and Arabic, plus Bengali, Italian, Dutch, Swedish, Danish, Norwegian, Finnish, Greek and Polish. The model detects your input language automatically, so you don't have to set it first.
That list is a reasonable match for a marketing team running campaigns in several markets at once. It's a different claim from saying the rewrite sounds equally natural in every one of those languages. Quality on a model like this typically varies by language, so a native reader should still check output in a language you don't speak yourself. A practical test is to humanize one short paragraph in each target language. Then have a colleague in that market read it before you run a full campaign through the tool. Our wider look at multilingual AI humanizers for international researchers covers what to check before you trust that kind of rewrite.
AIUndetect pricing
On 2 October 2026, AIUndetect had a free trial and three paid tiers: Basic, Standard and Pro. Every tier can be billed monthly or yearly.
Free limits
New users get 500 words of free humanizing and 10 free AI-detector checks, separate from the 250-word cap on the anonymous demo widget. Budget that allowance as a trial.
A single 500-word blog introduction uses the entire trial in one submission. That makes the free tier better suited to testing the output than to doing real work before you pay.
Basic, Standard and Pro
| Plan | Monthly | Billed yearly | Monthly words | Words per request | Detector checks/day |
|---|---|---|---|---|---|
| Basic | US$10/mo | US$5/mo (save US$60/yr) | 10,000 | 500 | 30 |
| Standard | US$25/mo | US$10/mo (save US$180/yr) | 50,000 | 1,500 | Unlimited |
| Pro | US$45/mo | US$20/mo (save US$300/yr) | Unlimited | 3,000 | Unlimited |
Standard is AIUndetect's own recommended plan, and for most content teams it's the sensible one. US$10 a month on yearly billing covers 50,000 words, 1,500-word requests and unlimited detector checks. The jump from Basic's 500-word request limit to Standard's 1,500 matters more than the headline price, if you're pasting in full pages at a time.
A 3,000-word essay on each plan
A 3,000-word draft takes six passes on Basic's 500-word limit, two passes on Standard's 1,500-word limit, or one pass on Pro's 3,000-word limit. Basic's 10,000-word monthly allowance covers about three such drafts a month before you'd need to wait for the next billing cycle or move up to Standard.
Which plan makes sense
Basic suits someone rewriting a handful of short pieces a month and checking each one against the detector occasionally, such as a freelancer with two or three clients. Thirty checks a day is plenty for that pace of occasional, low-volume use. Standard's jump to unlimited detector checks and a 1,500-word request limit fits a content calendar with several posts a week. Pro's uncapped monthly allowance only pays off once you're well past Standard's 50,000-word ceiling. That's a high bar for most individual writers and freelancers to reach in a month.
Renewing keeps your leftover credits
If you use up your word allowance before the month ends, AIUndetect's FAQ says you can renew early. The new subscription keeps your previously earned credits, which is more forgiving than a hard monthly reset. That rule covers the website plans, and the API credits are handled separately.
AIUndetect's API, and who the service is for
Developers get a separate product at AIUndetect's API page, priced on its own schedule, apart from the regular website plans. A 30,000-word monthly API plan costs US$15 a month billed monthly, or US$7.50 a month billed yearly. First-time API users get two free calls before billing starts, enough to confirm the response format before you commit a plan to a production integration.
The API call itself takes a model parameter with three settings: 0 for more quality, 1 for a balance of quality and speed, and 2 for a more human-sounding result. An optional auto mode reprocesses the text automatically, at double the word cost. Each request also takes a registered email address and the text to rewrite, between 100 and 10,000 characters. A successful call returns a status code and the rewritten text in the response body.
AIUndetect's own FAQ is direct that the website credits and the API credits are separate pools. Buying one doesn't add balance to the other. The FAQ also says the two products target different users. The website is for individual writers and students. The API is for businesses that want to call the rewrite engine from their own code.
AIUndetect's homepage groups its use cases into three cards: Office AI Assistance, Academic Work Helper and SEO Content Creation. For researchers, the Academic Work Helper card appears next to the marketing and SEO cases. Our guide to humanizing an AI research paper covers what to check in citations and technical terms after any general rewrite. Students comparing options can also see our wider roundup of AI essay writing tools for the ethical and practical side of that decision.
Academic Writing Keeps Its Citations Here
ProofreaderPro.ai's humanizer is designed to lower AI scores while APA, MLA, Chicago, IEEE and Turabian citations stay in format, from US$19 a month.
See the academic humanizerAIUndetect Humanizer vs. ProofreaderPro Humanizer
AIUndetect is priced for volume, with unlimited words on Pro and a detector bundled into every plan. ProofreaderPro.ai focuses on academic writing, with a humanizer that protects citations.
| Feature | ProofreaderPro.ai | AIUndetect |
|---|---|---|
| Made for | Essays, theses and journal papers | Marketing, SEO and general content, plus a research use case |
| Words per request | 500 (Academic), 1,000 (Academic Plus) | 500 (Basic), 1,500 (Standard), 3,000 (Pro) |
| Monthly allowance | 25,000 words (Academic), 50,000 (Academic Plus) | 10,000 (Basic), 50,000 (Standard), unlimited (Pro) |
| Languages | 60+ languages (Academic Plus) | 20+ languages |
| Citations | Keeps APA, MLA, Chicago, IEEE and Turabian formats | General rewrite |
| Price | US$19 or US$29 a month (US$169 or US$259 a year) | US$10 to US$45 a month, or US$5 to US$20 a month billed yearly |
Price per word favors AIUndetect at the Pro tier, where the monthly cap disappears entirely. For a paper, the deciding factor is the citations. ProofreaderPro.ai's humanizer is built to leave a reference such as [3] in an IEEE-style paper exactly where it is. Our IEEE citation guide covers the format in full if that's the kind of paper you're editing.
AIUndetect Humanizer Alternatives
AIUndetect's closest alternatives are other humanizer-and-detector bundles priced for high-volume content work.
| Tool | Best for | Our write-up |
|---|---|---|
| ProofreaderPro.ai | Academic writing with citations and field terms | Academic AI humanizer |
| Undetectable AI | An established humanizer and detector with its own API | Undetectable AI alternative |
| HIX Bypass | Part of a wider AI writing suite | HIX Bypass alternative |
| Smodin | A multilingual suite built for students | Smodin alternative |
| BypassGPT | High-volume rewriting for web content | BypassGPT alternative |
| StealthGPT | Many languages plus a bundled detector | StealthGPT review |
AIUndetect and Undetectable AI
Both pair a humanizer with a detector and both sell a separate API. Undetectable AI is the longer-established brand. AIUndetect competes mainly on price, with Basic at US$5 a month on yearly billing and unlimited words on Pro.
AIUndetect and Smodin
Smodin's suite is built around student and multilingual writing, with many study tools in one account. AIUndetect focuses on humanizing and detection, plus a separate API for developers. Students who want one study suite will find Smodin a closer fit, and marketers who want volume and an API will find AIUndetect closer.
AIUndetect and HIX Bypass
HIX Bypass is part of the larger HIX AI writing suite, so one account covers several writing tools. AIUndetect is a standalone product with its own pricing and its own separate API. If you already use HIX's other tools, the shared account may matter more to you than AIUndetect's API.
Frequently asked questions
Q: Is AIUndetect free?
New users get 500 words of free humanizing and 10 free AI-detector checks, which is enough to test a page or two. Continued use beyond that needs a paid Basic, Standard or Pro plan starting at US$10 a month, or US$5 a month billed yearly.
Q: Is AIUndetect legit?
Yes. The service is run by AIundetect LLC, doing business as AI Undetect, with published Terms governed by Idaho law and a support address at supporter@aiundetect.com.
Q: How many words can AIUndetect handle per request?
It depends on your plan. Basic allows 500 words per request, Standard allows 1,500, and Pro allows 3,000, while the anonymous demo takes 250.
Q: Does AIUndetect have unlimited words?
Only on Pro, where the monthly word allowance is uncapped, though the 3,000-word per-request limit still applies to each individual paste. Basic and Standard both cap the month at a fixed total instead.
Q: How many languages does AIUndetect support?
More than 20, including Chinese, Spanish, Portuguese, German, French, Japanese, Korean, Russian, Hindi and Arabic, among others. The tool detects your input language automatically, and output quality can still vary from one language to the next.
Q: Does AIUndetect have an API?
Yes, priced separately from the website plans. A 30,000-word monthly API plan costs US$15 a month billed monthly, or US$7.50 a month billed yearly, and the two credit pools don't share balance. First-time API users get two free calls to test the response format.
Q: What happens to unused AIUndetect credits if I renew early?
AIUndetect's FAQ says a new subscription keeps your previously earned credits, which is more forgiving than a hard monthly reset.
Q: Does AIUndetect include an AI detector?
Yes. Every plan includes AIUndetect's detector, with 30 checks a day on Basic and unlimited checks on Standard and Pro. New users also get 10 free detector checks.
Q: Can I get a refund from AIUndetect?
Refunds aren't offered as a rule. AIUndetect's terms describe one exception: a credit refund request made within 30 days of the submission, reviewed on a case-by-case basis. Approved refunds come back as credits on your account.
Q: What are AIUndetect's four processing modes?
Manual, Auto-Perfect, Balance and General appear above the input box, and they set how the rewrite handles your draft. Try each on the same paragraph to see which one suits your writing.
Q: Does AIUndetect's API cost the same as the website plans?
No. The API has its own pricing, starting at US$15 a month billed monthly, or US$7.50 billed yearly, for a 30,000-word monthly plan. It isn't connected to the Basic, Standard or Pro website plans.
Q: Does AIUndetect work for academic writing?
AIUndetect lists an Academic Work Helper use case on its homepage, alongside marketing and SEO cases. If you use it for a paper, check your reference list and in-text citations afterward.
Q: Is AIUndetect good for SEO content?
AIUndetect names SEO Content Creation as one of its homepage use cases, aimed at bulk blog output. Ranking and readability depend on more than how human a paragraph sounds, which our SEO content humanizer guide breaks down in more depth.
Built for essays, theses and journal papers, with citations kept in format across five humanizer modes.
Dana is a content creator at ProofreaderPro, where she runs the daily blog and writing operations. She writes the articles on how the online editing platform works, and she handles customer messages every day, with a five-star satisfaction score to show for it.
