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Free AI Detector
Check whether a passage contains patterns often associated with AI-generated text. Get one clear 0–100 score, passage-level signals, and honest limits—without uploading your writing.
✓ 3 free checks daily✓ Text stays in your browser✓ No account required
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TEXT SAMPLE
Paste the writing you want to check
0 / 2,500 wordsAdd text
✓Private on-device check
Private analysis
Your draft stays on-device
Passage review
See what shaped the score
Honest limits
A signal, not proof
Read the score carefully
A signal for review.
Never a verdict.
The free AI checker compares the writing with patterns learned from both human and generated text. It also looks at rhythm and repetition. The final number describes similarity—not who wrote it.
- 0–29Low AI signal
Fewer learned AI-writing patterns appear in the sample.
- 30–59Mixed signal
The detector sees competing or inconclusive evidence.
- 60–79Elevated signal
Several patterns resemble generated writing.
- 80–100High AI signal
Strong similarity—but still not proof of authorship.
What this free AI detector checks
One model. Three useful lenses.
The result combines a compact language model with simple writing-pattern checks. That makes the score easier to inspect, but it cannot replace source history or human judgment.
Language-model similarity
A small open model compares the passage with patterns learned from human and AI-generated text.
Rhythm and variation
Sentence-length changes and structural variation add context to the model reading.
Phrase-level review
The strongest passages are surfaced so you can review the writing instead of trusting one opaque number.
Useful before the final decision
Check the writing in its real context.
Different writing tasks create different patterns. Use the AI content detector as a first-pass review, then compare the score with the source, editing history, and purpose of the draft.
Academic drafts
Review a complete section—not one isolated sentence—and keep citations, notes, and revision history in view.
Best with 150+ wordsArticles and blog posts
Check whether polished prose has become overly uniform, repetitive, or dependent on familiar generated phrases.
Use the pre-publication draftReports and emails
Screen longer business writing while remembering that templates and formal language can raise false positives.
Context matters more than one scoreAI-assisted revisions
Compare versions after a human edit to see which passages still carry the strongest generated-text signals.
Review the highlighted passages firstSample quality changes the result
Give the detector enough signal.
✓
Stronger sample
A complete paragraph or section in its original wording, with several sentence lengths and transitions.
!
Harder to judge
One or two sentences, bullet lists, quotations, code, poetry, translations, or text edited by several people.
“A longer sample does not make the detector certain. It simply gives the model more language patterns to compare.”
Built for a careful first pass
Free to check.
Responsible by design.
An AI content detector can misread polished human work, heavily edited AI text, translations, formulaic academic writing, or very short samples. Use the result to ask better questions—not to make automatic accusations.
- Use at least 80 words when possible.
- Compare the original source and revision history.
- Never treat a score as standalone evidence.
Why AI detectors disagree
The same text can produce different scores.
An AI checker does not look up who wrote a passage. It estimates patterns using a particular model, training set, and scoring threshold. Another detector may weigh predictability, vocabulary, sentence structure, or repetition differently.
That is why a ChatGPT detector, a general generative AI detector, and a classroom tool can disagree on the same sample. Treat disagreement as a reason to inspect the text—not as a reason to keep rerunning tools until one returns the score you want.
Found passages that sound too uniform?
Make the writing clearer,
not just the score lower.
Use UltraHumanizer to revise rhythm, phrasing, and readability while keeping your meaning visible for review.
Open the free AI Humanizer ↗Practical guide
Use an AI text check in a complete review
How to check AI writing without losing the context
Choose a representative passage rather than a single sentence. This AI text detector accepts 40 to 2,500 words and recommends at least 80; it is best suited to English prose. Keep the paragraph in its original order, and avoid filling a short sample with repeated text merely to reach the minimum. Quotations, lists and technical material can make the result less representative of the surrounding writing.
After the model loads, review the passage signals alongside the overall reading. If a section is flagged, ask what makes it repetitive, formulaic or unusually uniform. A ChatGPT checker cannot look up the conversation that produced a draft, and this tool does not reliably identify a particular generator. Draft history, source notes and a discussion with the author answer different questions from a model score.
AI detection, plagiarism and grammar checks answer different questions
Choose the check that matches your task. Running an unrelated checker can produce a convincing-looking result without answering the question you actually have.
Scroll sideways to see all columns.
| Question | Appropriate review |
|---|---|
| Does this prose resemble learned AI-writing patterns? | Use the AI detector as one signal, then inspect the passages and writing history. |
| Are sentences grammatically correct? | Use Grammar Checker and accept corrections individually. |
| Is the explanation easy for my audience to read? | Use Readability Checker and review the longest sentences. |
| Was text copied from another source? | Check original sources and attribution. This AI detector does not search a plagiarism database. |
- Check the same complete passage when comparing edits.
- Treat conflicting detector readings as uncertainty, not evidence that one result must be correct.
- Keep source citations and revision records when you need to explain how a document was created.
Questions, answered
Free AI text detection,
without false certainty.
Is the UltraHumanizer AI detector free?+
Yes. Free users get 3 AI text checks per day, with no account required. Basic, Pro and Ultra include unlimited daily uses. The allowance resets at 00:00 UTC, and the compact detection model runs in your browser.
Does the AI text detector upload or save my writing?+
No. The page downloads the detection model and analyzes the text locally in your browser. Your draft is not sent to UltraHumanizer or written to its database.
Can an AI detector be 100% accurate?+
No. AI text detectors can produce false positives and false negatives, especially with short, edited, technical, or multilingual writing. A score should guide review, not prove authorship.
Is an AI detector the same as a plagiarism checker?+
No. This tool examines writing patterns in the supplied text. It does not search published sources or establish whether text was copied. Review original sources and citations separately.
Which language does the AI text detector support?+
This model is best suited to English prose. Other languages, translations, code and heavily structured text can produce unreliable readings. The tool warns when the input is unsuitable.
How much text should I check?+
For a more useful reading, paste at least 80 words. Longer samples give the detector more rhythm, repetition, and phrasing patterns to compare.