Most free AI detectors hand you a single percentage and hope you do not ask where it came from. TextSight Free runs the same classifier Pro runs, surfaces sentence-level evidence on every scan, and keeps the result page clear of ads. Three scans a day at up to 1,500 words each, a free account with no card needed, and the same measured false-positive rate we publish for the paid tiers. Accuracy on the free tier matches paid tiers within rounding because there is no separate free-tier model. Only the daily quota differs.
Three scans a day, 1,500 words per scan, and the full evidence panel. The numbers below are exactly what you get on the free tier with no upgrade gate.
Resets on a rolling daily window. Three scans cover the most common cases the free tier serves: a pre-submission essay check, a freelance deliverable review, and a quick sanity pass on a short article. Heavier daily volume is the line where free moves into Starter or Pro, but it is also the line where ad-funded free clones start to break.
Long enough to cover most essays, blog posts, and product descriptions in a single scan. Longer documents can be split into sections, or run through the higher per-scan caps on Starter (5,000 words) and Pro (7,500 words). The free per-scan cap is a real cap, not a teaser-grade quota that hides the actual usable text length.
Green for human, yellow for borderline, red for AI. Free scans highlight the first lines of your text and Starter and up highlight every sentence, so a global score is always paired with the underlying evidence. This is the feature most free competitors gate behind paid plans, and the reason their free percentages feel unactionable.
Returned alongside the Humanization Score on the same scan. A simple flag highlighting passages with a higher chance of overlap against indexed sources. Not a full plagiarism report (that lives in the Plagiarism tool), but enough to know whether the AI score is the only thing worth thinking about for a given piece.
There is no quiet downgrade on the free tier. The classifier, the calibration, and the scoring scale all match the paid tiers within rounding. Only the daily quota differs.
We do not publish an accuracy percentage, because accuracy moves with text length, genre and the model that wrote the text, and formal, encyclopedic human writing is the kind most likely to be wrongly flagged. Long-form, unedited model output is where detection has the most statistical signal to work with.
Short text under 200 words gives any classifier in the category far less statistical signal to land confidently on. The result panel surfaces a low-confidence flag on short text so you know to treat the score as suggestive rather than precise.
We ran the detector over 1,180 human-written academic papers published in 2018. Every one predates ChatGPT, so every AI flag it returns is a false positive by construction. It wrongly flagged 5.85%, 95% confidence interval 4.65% to 7.34%, and a further 20.0% came back Mixed or Uncertain rather than a clean human verdict. We train on second-language academic prose to reduce false positives on it and we checked whether that worked: second-language writers were flagged 4.6% of the time against 8.1% for native writers, a gap whose confidence interval of [-9.9, +2.1] percentage points crosses zero, so the honest statement is no significant difference in either direction. The per-document dataset is downloadable. The free tier runs the same detector, so the same number applies.
Any tool advertising 99 or 100 percent is quoting a best-case test set, not real-world performance. Treat the Humanization Score as a calibrated signal, not a verdict. Pair it with the sentence-level highlights to see which paragraphs are driving the result, then make an editorial call from there. This page does not promise anything that detection cannot deliver.
Three scans a day on free, unlimited on Pro. The classifier is identical on every plan; free highlights the first lines, Starter and up every sentence. Yearly billing saves 25%.
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The free tier is designed so a single scan runs end to end in about thirty seconds on an 800-word essay, once you have a free account.
Open app.textsight.ai. Paste up to 1,500 words into the detector tab. The word counter ticks as you type or paste, and you only need a free account, no card. Three scans a day means you can run three independent texts through the same workflow before the daily cap applies.
Click Scan. The full classifier runs in roughly six seconds on short text and thirty seconds on an 800-word essay. The result panel returns a 0 to 100 Humanization Score, the five-band confidence label (Original, Mostly Human, Mixed, Likely AI, AI Generated), and the Plagiarism Risk indicator on the same scan.
Open the per-sentence panel. Every green sentence reads human. Every yellow sentence is borderline. Every red sentence is flagged AI, with its own AI score. Free highlights the first lines; Starter and up show every sentence. The highlights are the evidence that turns a calibrated score into a call you can defend in a conversation with a student, editor, or freelancer.
Use the highlights to edit, escalate, or move on. If the score is borderline and you need more confidence, scan a second draft after editing the red sentences. The free tier is generous enough for genuine pre-submission work, and the upgrade path to Pro is open the moment three scans a day is not enough.
Three structural reasons explain why most of the free results returned by a "free AI detector" search feel unactionable in real use.
Tools funded entirely through ads run lighter classifiers on the free tier because a full transformer per scan costs real money. Lighter classifiers trained on GPT-3.5 era data have not kept up with GPT-5, Claude 5, and Gemini outputs, so the percentage they return is often noise. TextSight keeps the same classifier on free that Pro uses, because the free tier is paid for by Pro subscriptions rather than by the result page itself.
Most free detectors return a single score. A score with no per-sentence colour map tells you the number, not the reason. A 65 percent "AI" reading with no underlying signal is impossible to act on, and that is the experience most "free AI detector" search results deliver. TextSight Free includes sentence-level highlights on every scan because evidence is the difference between a usable score and a number you cannot defend.
Banner ads above the highlights, upsell prompts pasted over the score, interstitial ads when the result loads, and aggressive newsletter modals are standard on ad-funded free detectors. The result page itself is the product they monetize, which is why the actual highlights feel cramped. TextSight Free is funded by paid tiers, not ads, so the result panel stays clean.
Top 6 free-tier tools ranked honestly. Where TextSight wins, where the alternatives are tolerable.
See the ranking →Sentence-level evidence and a published false-positive rate on the GPT-4 focused detector.
Open the detector →Multi-model detection across GPT, Claude, Gemini, and Llama with the same evidence panel.
Read the page →Full tier breakdown for Free, Starter, Pro, and Business. Annual billing saves 25%.
See pricing →Same classifier as Pro on every free scan, sentence-level highlights included, false-positive rate published. Three scans a day with a free account, no card needed.
Other free ways to check text for AI.