Free AI Detector.
Paste text. Get a verdict.
A free AI content detector with no signup and no word limit. Paste any text up to eight thousand words and find out in seconds whether it reads as human or AI. When something needs fixing, rewrite it in one click on the same page.
No signup. No word limit. Built into the same engine that rewrites tens of thousands of words a day for paying users.Want to rewrite text instead?
Real writing. Real stakes.
This is the detector to reach for when the decision actually matters. An essay you are about to submit. A piece a client is about to receive. A draft your editor is about to open and read. Pages where the wrong AI flag has consequences that travel beyond a percentage score.
Students and researchers
Check an essay, a paper, a thesis, a discussion post before submission. See the verdict, see which sentences look AI, and rewrite only those sentences without redoing the whole document. Works equally well on short classroom assignments and long form research write ups. Useful at the start of a draft to catch obvious tells before they multiply, and useful at the end to confirm the final version stands on its own.
Freelance and SEO writers
Check a piece before sending it to a client or pasting it into a content management system. Catch the sentences that read AI and fix only those, keeping your voice and the structure the brief calls for intact. Especially useful on assignments where the client policy is no AI assistance, where one suspicious paragraph in the middle of an otherwise solid draft can sink the whole invoice.
Editors and publishers
Run inbound submissions through a quick verdict before you commit time to a closer read. Sentence level highlights save the time of scanning every paragraph just to find the one that gives a piece away. Verdicts are calibrated so polished human writing does not get flagged on the basis of polish alone, which used to be the failure mode of earlier detectors and pushed editorial teams off them.
ESL and non native writers
Earlier generation detectors were notorious for flagging non native English writing as AI. We built this engine specifically to be honest with simpler, cleaner prose. The borderline band is wide on purpose so legitimate human writing does not get punished for not having native flourishes. If you write English as a second language and have been burned by a detector that called your real essay AI, this is the tool worth a second chance on.
A clear read. Not a wall of numbers.
The point of a detector is to give you something you can act on. A raw percentage by itself does not do that. You still have to interpret what the number means and what to do about it. The verdict we return is built around the decision you are actually trying to make.
Three buckets, no jargon
Likely Human, Borderline, or Likely AI. No raw percentage to interpret. No graph to read. You get a clean call you can act on without needing to know what the underlying score means or how it was calculated.
How sure the engine is
A confidence reading next to the verdict tells you whether to act on the call immediately or pause and inspect the flagged sentences first. A confident Borderline tells you something different from a borderline Borderline.
Which sentences look AI
Every sentence is read individually and tagged. Spot the ones that need rewriting without reading the whole document twice. Saves significant time on long pieces where the AI sounding sentence might be one of fifty paragraphs.
Why it stays free.
The detector is the first half of a longer workflow. People who want to check their text often also want to fix it once they see the read. Fixing the writing is what HumanGPT was built to do. Making the detection step free, with no signup and no word limit, is the right way to introduce the engine, and it is also the right way to run the funnel.
Paying users power the rest of the platform. The multi pass rewriter, the long form rewrites, the API, the brand voice training feature, the priority queue. The detector itself stays free because it should be. Knowing whether a paragraph is going to get flagged by the people who read your work is not a thing anyone should be asked to pay to find out.
No card on file, no signup, no daily cap on how many checks you run. Sign in if you want your check history saved across sessions, if you want the deeper sentence by sentence view, or if you want to opt in to helping us train the next version of the engine. Stay anonymous if you do not. Either way the verdict you see is the same.
The check, rewrite, check loop.
Likely Human. The writing reads as human and is unlikely to be flagged by the people or systems that will see it next. Submit, publish, or send with confidence. No further action needed unless you want to keep iterating on the writing for editorial reasons of your own.
Borderline. Some passages might be flagged depending on which detector or reader receives the text. Look at the sentence level read, identify the borderline and AI tagged sentences, and rewrite just those. Cleaner than rewriting the whole document and faster than running an additional editing pass over text that mostly already works.
Likely AI. Most detectors and most close readers will flag the writing as AI. Click the Rewrite this text button. The rewriter runs a multi pass rewrite that preserves your meaning and structure but lifts the verdict back into Likely Human territory. Paste the new version back into the detector to confirm before you send it on.
The full loop, check, rewrite, recheck, takes around one minute on a five hundred word essay. If a passage still reads Borderline after one rewrite pass, switch the rewriter into Heavy mode and run it again. By the second pass the verdict is almost always Likely Human even on text that started as obvious AI output. For long pieces, break the text into sections of around two thousand words, run each section through the loop, and stitch them back together at the end. The verdict on each section is independent so the loop scales cleanly.
Five situations where this tool earns its place.
A paper due tomorrow morning
The draft is written. You worked on it yourself. You wrote it in your own voice and you stand behind it. You want to check before you submit because the school system has detection running on every submission and a false flag costs more time than the check does. Paste the paper. Read the verdict. Move on.
A client piece with a no AI policy
Writing a piece that used some AI assistance during research and outlining but ended up rewritten by you in your voice. The client policy says no AI. You want to be sure the rewrite landed on the human side of the line before you invoice. Paste, check, rewrite the borderline sentences, send.
An editorial inbox triage
Twenty pitches landed overnight. You want to know which deserve a close read and which were dashed off through a chat interface. A quick verdict on each lets you spend your real reading time on the ones that earned it. Sentence level highlights let you confirm the call at a glance.
A scholarship application
The personal essay matters. The committee reads hundreds. A piece that pings as AI written gets thrown out before a human evaluator even reads the sentences. You want to confirm your authentic voice survives the screening pass. Paste, check, rewrite the borderline sentences in your own words, submit.
An ESL essay graded by a non native reader
English is your second language and your professor has been heavy handed with the AI accusation this term, even on writing you did entirely yourself. You want a calibrated read that does not punish you for clean simple English. Paste the essay, see the verdict, and you have an objective second opinion you can stand behind if the conversation comes up.
A blog post for an SEO client
The piece needs to read as human writing for both Google quality signals and for the audience that will actually skim it. You want a quick verdict and the option to rewrite the AI tagged sentences in seconds. Same page, same engine, no copy paste across five tabs.
Updated weekly for 2026 models.
AI writing changes fast. A new flagship model lands every few months, and the patterns that gave the previous generation away change with it. We retrain the engine weekly against fresh outputs from the leading current generation models, including GPT class, Claude, Gemini, Llama, and others. That is the only honest way to keep a detector working as the underlying models evolve.
Every Sunday the engine ships a new version. The version pin on each detection result, visible at the bottom of every check, tells you exactly which build returned the verdict. Screenshots and shared results remain attributable even after the engine improves. Old verdicts stay tied to the engine version that produced them so the historical record is intact.
We benchmark against the same model families that drove the rise of AI detection in the first place and against the newer rewriter style outputs that older detectors miss. The result is a read that survives both raw AI output and lightly edited AI output. A piece that was generated by a recent model and lightly polished by a writer should still register honestly, which is the case where most consumer detectors fail.
The retraining pipeline is automated end to end and supervised by a small team. New training data is reviewed for distribution balance before it lands in the engine. Test sets are pinned so each new version is graded the same way as the version before it. If a release would degrade the verdict on writing the previous version handled correctly, the release is held back until the regression is fixed.
AI Detector FAQ.
Honest answers.
Yes. Actually free, actually unlimited. No card, no account, no daily cap on detection. Paste your text, click the button, get a verdict. The humanizer side of the platform has a generous free daily allowance and unlocks more on Pro, but the detector itself sits at zero cost forever. Run it as many times in a day as you want.
Usually under five seconds for a paragraph or short essay. Longer documents take a little more. An eight thousand word paper finishes in around twelve seconds end to end. We process locally where we can and route through high throughput inference for the rest, so there is no queue and no random slowdown during peak hours.
Yes. That is the most common reason people open this tool. Paste your essay, read the verdict, and if it lands on Borderline or Likely AI, click the Rewrite button so the engine reshapes only the flagged sentences. You can check, rewrite, and re-check as many times as you want before turning the paper in. The full loop takes around one minute for a typical five hundred word essay.
Between one hundred and three thousand words is the sweet spot. The minimum we accept is fifty words because anything shorter is statistically unreliable and we would rather say so than guess. The maximum per single check is eight thousand words. For longer documents, split into sections and check each one independently.
Yes, including every current model family. The signal we read is statistical, not model specific. Whether the text came from a GPT class model, a Claude variant, Gemini, Llama, Mistral, or any other recent model, the same engine reads it. The model coverage is refreshed weekly against fresh outputs from the leading current generation systems so the read stays current as new versions ship.
False positives are the failure mode we work hardest to avoid. The verdict has three buckets. Likely Human, Borderline, and Likely AI. Borderline is deliberately wide. If your writing is clean, polished, formal academic prose, the tool will say Borderline rather than calling it AI outright, which gives you room to act without forcing you into a rewrite you did not need. If you are an ESL or non native English writer, the borderline band protects you from the false positive bias that hit earlier generation detectors.
Yes, and the engine was tuned specifically for this. Earlier detectors had a documented bias against non native English writing, flagging clean simple prose as AI at sharply higher rates than native writing. That bias was the bug we set out to fix when we built our own engine. The three bucket verdict with a wide borderline band gives non native writers an honest read instead of a punishing one. If your verdict lands on Borderline and you wrote the piece yourself, that is the engine telling you to stand behind your work.
Yes. After the first detection, if the verdict is Borderline or Likely AI, click the Rewrite this text button. The text pre loads on the home page rewriter. After the rewrite finishes, paste the new version back into the detector and watch the verdict shift. In most cases a single rewrite pass moves a Likely AI verdict into Likely Human territory. If a piece still reads Borderline after one pass, switch the rewriter to Heavy mode and run it again.
By default, no. We keep a one way hash so we can rate limit abuse and a short preview for log review. The text itself is not stored unless you are signed in and have explicitly opted in to the Help improve the detector setting on the account page. That setting is off by default. Anonymous checks cannot be reconstructed from our logs. If you opt in, retained text is used only to retrain the engine, never resold, never shared, and you can opt out and delete at any time.
Batch detection is available on the API. Authenticated Pro and Founder users can post up to fifty texts in a single request to the detect endpoint. The free web tool stays single text by design so the paste, check, decide flow stays as fast as possible. Documentation and example requests are on the API page in the navigation.
Same engine, different surface. The home page meter is the rewriter view. It reads the text from the perspective of writing flow and is wired directly into the multi pass rewrite loop. The dedicated detector page here gives you the same engine at full resolution with sentence by sentence highlights so you can see exactly which sentences land on borderline or AI. Both meters move together. If one says Likely Human the other will too.
It tells you how decisive the read is. Ninety five percent confident on a Likely Human verdict means the engine is sure and you can submit without a second pass. Thirty five percent confident on a Borderline verdict means the engine sees mixed signals and the text could go either way depending on which downstream detector receives it. Worth rewriting the flagged sentences in that case even if you are technically below the AI threshold.
Yes. Pro and Founder users get an API key that authenticates against the same engine the website uses. Single text and batch endpoints are documented on the API page along with rate limits and example requests in JavaScript, Python, and curl. An MCP connector for use inside Claude Desktop and other MCP compatible tools is in private beta. Sign in and watch your account inbox to be invited when it goes public.
Three honest reasons. First, the verdict is genuinely confident at strict false positive control, not a hand wavy percentage you have to interpret. Second, when the verdict lands on Borderline or Likely AI, you can fix the writing on the same page in one click rather than copying text between five tabs. Third, the detector itself is free at the entry point and stays free for individual users. Paying users power the rewriter and the API, which is the right way to fund a tool that everyone benefits from at the detection step.
The rewriter is a multi pass engine that varies sentence structure, swaps overused phrasing for natural alternatives, and preserves your meaning and intent. Free users get unlimited detection and a generous daily allowance of rewriter words. Pro at ten dollars per month unlocks fifty thousand monthly rewriter words, the API, the brand voice training feature, and the multi pass rewrite loop that keeps running until the text lands on Likely Human. Founder is a one time payment that removes every cap permanently.
The version that returned your verdict is pinned in the result so screenshots and shared results stay attributable as the engine improves. We retrain weekly against fresh model outputs and roll the new version forward every Sunday. The same text checked next month will likely return a slightly different score because both AI writing patterns and our reading of them evolve. We never silently rewrite history. Old verdicts remain tied to the engine version that produced them.
Clean academic prose, long form journalism, well edited business writing, and any text that has been polished through several editing passes. The reason is mechanical. Polished writing converges on certain rhythm patterns, certain vocabulary patterns, certain sentence length distributions. AI text converges on the same patterns. The two overlap in the middle. The Borderline bucket is the engine telling you the read is genuinely ambiguous, which is honest information, not a failure of the verdict.
Free check. One click rewrite. Send your work with confidence.
Use the detector as many times as you need. When something needs fixing, the rewriter handles it on the same page. The whole loop is built into one tool, free at the entry point and ready to do real work.