Humanize AI is a free alternative you can open and use right now. It gives you an AI checker and a one-click humanizer on ten credits a day, counted per network, with no account, no login, no card and no email address. There is nothing to verify and nothing to cancel. Paste at least 65 words, run the check for a 0 to 100 score and a plain label, rewrite the passage in one click, then check it again. A separate set of writing tools, including a registry of named AI writing tells, runs in your browser with no credit cost and no daily cap at all.
Most people typing that query are not shopping for a brand. They are trying to get past four specific obstacles: a signup wall standing in front of the thing they want to try, a subscription commitment when the work in front of them is one deadline long, a card field that turns a five-minute task into a billing decision, and a rewrite they cannot evaluate because nothing on the screen tells them how the text reads afterwards.
It also helps to be precise about the word undetectable. It has become the generic name for this whole category of tool. Undetectable AI is a separate product from a separate company, and this site has no connection to it. As a description of an outcome, the word promises more than any tool can hand you. Detection results come from third-party classifiers that their owners change on their own schedule, and each one makes its own call. What a rewriting tool can do is change the text and show you a reading before and after. What a detector reports afterwards is that detector's call.
The checker takes a passage of at least 65 words and returns an AI score from 0 to 100 with one of three labels: Reads as AI-generated, Borderline, or Reads as human-written. It takes seconds. A run costs one credit whatever the length, so scoring a full chapter costs the same as scoring a paragraph.
The humanizer rewrites every sentence in the passage in one click. A single run takes up to 12,000 characters, which is roughly 2,000 words, and it needs at least 25 words to work with. It costs one credit per 50 words, so the price tracks the size of the job rather than the number of times you press the button.
The normal loop is check, rewrite, check again. The second check is the point of the exercise, because it shows you where the score landed instead of leaving you to guess.
The free tier is ten credits every day, counted per network, and it refreshes daily. No account is attached to it, which also means there is nothing to cancel and no renewal date to keep track of.
Ten credits covers one check, 400 words of rewriting and a second check, which comes to exactly ten. That is enough for a cover letter, a personal statement, a short application essay, a blog post, or the two paragraphs of a longer piece that are pulling the score up. Because a check costs one credit at any length, you can score a 5,000-word draft for a single credit and spend the other nine on the sections that need the work.
Longer projects run in sections. Putting a full 2,000-word essay through the rewriter costs 40 credits, so it spreads across four days of free use. The faster route is to rewrite the 400 words carrying most of the machine-made reading, with a check on either side, which fits inside one day of credits, and to hand-edit the rest. The tell registry below is what makes the hand-editing quick enough to be worth doing.
Alongside the metered checker and humanizer, a set of tools runs in the browser with no daily limit and no credit cost.
The registry is the one that stretches the credits furthest. It names the constructions instead of just shading a paragraph red, so you can see the stock opener, the not X but Y pivot and the announced conclusion sitting in your own sentences and cut them yourself. Fix the ones you recognise by hand, then spend the rewrite on the passages that resist editing.
This site does not tell you what a given detector will say about a given paragraph on a given day, and it does not claim to. Those classifiers are private, their owners change them when they choose, and they do not show how a reading was produced.
The clearest published number on how wrong they can get it comes from Liang and colleagues at Stanford HAI in 2023: across seven detectors, 61% of TOEFL essays written by non-native English speakers were falsely flagged as AI-generated. Those essays were written by people. That is the reason to treat any detector output as one opinion rather than a verdict, and it is why the score here sits next to the free tell registry, which names the exact phrases behind a machine-made reading instead of leaving you with a number on its own. The mechanism behind those false positives, and what to do when one has already landed on you is at you wrote it and were accused.
One paragraph on policy and then back to the tools. Rewriting a draft you were permitted to generate is ordinary editing. Where AI is not permitted, that rule covers the draft however it is edited. Course policies differ from each other and from employer policies, so read the one that applies to you.
If your interest runs the other way, which is proving that writing you did yourself is yours, the signed drafting record keeps evidence of the draft as it was written, and verify a report checks one of those reports in the browser against the key the report carries. The pages at for teachers and for second-language writers cover both sides of that in more detail.
No. There is no account, no login, no card and no email address, and nothing to verify. The free tier is ten credits a day, counted per network, and it refreshes daily. Because nothing is registered, there is also no subscription to cancel.
A check costs one credit whatever the length, from a 65-word paragraph to a full chapter. A rewrite costs one credit per 50 words. So a day of ten credits is, for example, one check, 400 words of rewriting, and a second check to see where the score landed, which comes to exactly ten.
One run takes up to 12,000 characters, which is about 2,000 words, with a minimum of 25 words. Anything longer is run in sections, one at a time. Checking has a minimum of 65 words, because the checker needs at least that much text to return a stable reading.
This site does not promise that. What it does is rewrite every sentence, give you a score before and after, and, through the free tell registry, name the constructions producing the machine-made reading. What a third-party detector reports on a given day is its own call, on a classifier its owner can change at any time.
Both draw on the same ten daily credits. The in-browser tools are separate and are not metered at all: the tell registry, the proofreader, the word counter, the readability checker, the AI vocabulary checker, the originality and plagiarism check, and the signed drafting record all run with no credit cost and no daily cap.
Your course policy decides that, and it is the only thing that does. Rewriting a draft you were permitted to generate is ordinary editing. Where AI is not permitted, that rule covers the draft however it is edited. Read the policy that applies to you.
Paste at least 65 words into the box at the top of this page and run the check. If the label comes back as Reads as AI-generated or Borderline, switch to the humanizer, rewrite the passage, and check it again. On a 100-word passage that loop costs four credits: one for each check and two for the rewrite. Each check takes seconds.