Free AI Detector and Humanizer

What Is an AI Detector and Humanizer?

Quick answer: An AI detector and humanizer scores your text for how AI-like it reads, rewrites it in plainer wording, then scores the rewrite, so you see both numbers side by side. Paste your text in the tool above and compare them.

This AI text detector and humanizer runs a classifier, which attaches an AI probability to your text, then a language model that paraphrases it. It is an editing pass, not a disguise, and not a plagiarism checker, grammar check or readability score. Blog posts, product descriptions, emails and cover letters get the same steps. It promises no result against any other detector.

How to Detect and Humanize AI Text

This free AI detector and humanizer is one box and one button; only the waiting is out of your hands.

1. Paste your text. The box takes 50 to 1,800 characters, about 300 words, and silently keeps only the first 1,800 if you paste more, so split long documents. Your text stays in the box after you press the button.
2. Press Detect and Humanize. The page reloads with a waiting card. The tool takes one run at a time, so press once.
3. Wait for the result. A progress bar and an Elapsed timer run while the headline names the stage: checking the AI score, Loading the AI model and reading your text, then Humanizing (part 2 of 3 on longer text). Behind other runs it says Waiting in line, and Cancel stops the run. A timeout shows 'Our free AI server is very busy right now and could not finish in time.' and keeps your text.
4. Read, copy and compare. The card shows AI score before, AI score after and a Humanized Text box with the rewritten version. Copy flips to Copied, and Run another gives a blank form.

Tip: Short text swings. One Huckleberry Finn excerpt scored 22.9 at 276 characters and 0.6 at 1,441, so check a longer passage in the tool above.

How to Read Your AI Score Before and After

The score is the detection model's probability score, from 0 to 100, that the whole text is AI generated. It is not proof, and not the share of sentences a machine wrote.

This page prints each score as a percentage in that color and adds no verdict words, and yellow and amber are close shades, so go by the number. The AI Content Detector page uses the same bands and adds the words in the last column.

A given text always gets the same before score, but each rewrite is new, so after scores can differ. Matching high numbers, like our 100 and 100, mean the displayed score did not move. A higher after number, like 62.8 to 99.5, means the new wording read as more AI-like to this detector.

What We Saw When We Tested It

We pasted texts into this AI detector and humanizer as a guest on October 16, 2026, before the box was capped at 1,800 characters. An AI model wrote the stock, casual and business paragraphs, and the figures paragraph was invented. Human written samples come from Project Gutenberg, cut at a sentence end and scored by the detector alone, though one still carried a bracketed picture caption.

That is seven finished runs on four texts. In that first round the rewrite never lowered the score and raised it twice. The business text came back 16 percent shorter, minus a sentence on job satisfaction studies. The figures rewrite stopped at 'citing a 37% increase in' because a length cap counted letters only; the page now counts words.

On October 17 we ran the figures paragraph twice more. At a load average of 9 to 15 the first score gave up after about 30 seconds and the run stopped at 222 seconds with the busy message, so it has no after score. At a load near 5 to 7 it finished in about 78 seconds: 90.2 before, 81.9 after, still red, ending on a full sentence. One run each is an anecdote.

Where you cut matters. The first 520 characters of the Pride and Prejudice opening, cut at a sentence end, scored 36.8; cut five characters short, mid-sentence, they scored 57.0, crossing from yellow into amber. Stray text matters too: the 1,440 character excerpt carried that Gutenberg picture caption in square brackets and scored 52.2, against 30.6 without it. A score is a reason to read the text, not a verdict. Run your own text in the tool above.

How the AI Detector and the Humanizer Work

Three steps run in order on our own server, all on CPU: the detector, the rewrite model, then the detector again. No outside AI service is involved.

Our detector is a fine-tuned classifier, DeBERTa v3 large, an open model under the MIT license (see the desklib/ai-text-detector-v1.01 model card on Hugging Face). It reads at most 768 tokens, a token being a word fragment, and silently ignores the rest, which English text inside the 1,800 character box stays under. The card cites the RAID benchmark but publishes no accuracy figures, so we quote none.

The rewrite comes from Qwen2.5 7B Instruct, run through Ollama (a local model runner) as a 4-bit build, a compressed copy that fits CPU inference, on four threads, one per physical core. Text over about 110 words is cut into parts, each its own request. The prompt asks for text that reads naturally, with the same meaning, facts and language, varied sentence length, plain wording, less robotic phrasing, less repetitive phrasing, roughly the same length and no em dashes. At temperature 0.8, the randomness setting, two runs usually differ.

Limits to Know Before You Start

• Length. The box takes 50 to 1,800 characters, but that character limit is no promise: a busy server timed out our 226 character test on October 17.
• Text only. You get one rewrite per run, with no file upload, web address box, batch mode or tone setting.
• English text. The detector was built for English, and in our tests AI-written Chinese and Russian scored anywhere from 1.6 to 82.3. A 200 character Chinese paragraph counts as one word for the length cap, which leaves room for only 27 tokens, and in our October 17 test it ended with 'The AI returned no text for this input.' after its first score, 1.6.
• Cut-off and shortening. The rewrite is a light edit that can drop detail, and in our first round it ran 5 to 27 percent shorter. When a part reaches its length cap, the page keeps whole sentences and the card says some were left out.
• Waiting. Jobs run one at a time in a shared processing queue, so busy hours mean a longer wait time. With five requests already in line the page asks you to try later. After about 220 seconds a run stops: finished parts are kept, the rest stays your own wording, the card says so, and with no finished part you get the busy message.
• Scores are advisory. The result card says 'AI detectors are not fully accurate. Use the score as a guide.' Our caption and cut-point tests show why.

Using a Humanizer Honestly

If a school, employer or client has an academic integrity or AI use policy, follow it. Editing AI generated text does not release you from it, and this page is not a way to hide AI use. Where disclosure is required, hold on to your drafting history.

In a 2023 study of GPT detectors and non-native English writers, the detectors flagged that writing as AI generated. Never judge a person on one score. Read how AI detectors work and when they fail, or follow how to make AI writing sound human to edit by hand.

What we do not promise: a result against any detector.

Which Tool Do You Need: Detector, Humanizer or Both?

This page shares the free AI humanizer's rewrite engine and prompt, and adds the two scores.

Around a run, three more pages help:

• Online Text Editor: clean up the copied rewrite.
• Image to Text Converter: pull text out of a scan first.
• all free AI tools: the rest of the category.