A text compare tool built for essays, articles and documents, not just code. Paste two versions and see every changed word, every rewritten sentence and every moved paragraph in seconds. Free, no signup, and nothing ever leaves your browser.
Compare any two versions of a text, document or email.
Paste either side into the GPTOne AI detector to score text from ChatGPT, Claude, Gemini and DeepSeek. Free credits on signup, no card required.
Check text for AICheck whether a photo or graphic is AI-generated. Metadata and provenance checks run in your browser; the full forensic scan uses one free credit pack.
Detect AI imagesDiffchecker, DiffNow and Text-Compare were built for source code. This one was built for the way people actually edit writing.
Highlights the exact words that changed inside a paragraph, in a proportional font you can actually read. Switch to sentence mode to see rewrites at a glance.
Reordered a section? A line diff shows a block of deletions and a block of additions. This tool labels it as moved and keeps your similarity score honest.
Paste your draft and the ChatGPT, Grammarly, Quillbot or Claude version. See what the AI swapped, how many sentences it rewrote, then check either version for AI.
Compare a draft with the final, or two submissions with each other. Shared passages stay quiet, rewrites light up, similarity is one number.
The comparison runs in your browser. No upload, no account, no server log. Compare contracts, grades or medical notes without a second thought.
A share link packs both texts into the address itself, after the # symbol, which browsers never send to a server. Nothing is saved on GPTOne.
No compare button to hunt for. The diff updates as you paste or type.
Put the original text in the left box and the changed version in the right box. Essays, articles, emails, contracts, Markdown or code all work. Nothing is uploaded.
Deleted words appear in red with a strikethrough, added words in green. Paragraphs that only moved are labelled instead of being shown as deleted and re-added. Switch to sentence, line or character granularity when you need a different level of detail.
The similarity percentage and the counts of words added, words removed and sentences rewritten tell you how heavy the edit was. One click sends either version to the GPTOne AI detector.
Compare a student's draft with the submitted final to see whether feedback was applied, or compare two submissions to spot shared passages. Then run the suspicious version through the AI detector.
See exactly what ChatGPT, Grammarly or Quillbot did to your paragraph before you accept it. Keep your voice, take the fixes, and know how much of the text is still yours.
Compare your first draft to your final version, check what a proofreader changed, or confirm a paraphrase is different enough from the source before you cite it.
Compare two versions of a contract clause, policy or terms page and find every changed word without uploading confidential documents to a third party.
Review what a writer changed between revisions, compare an article to its republished version, or check how much a rewrite really differs from the original.
Line mode gives a classic text diff for config files, JSON or SQL when you do not want to open a terminal. For big code reviews your IDE is still the right tool.
Those tools are excellent for code. For writing, these are the differences that matter.
| Feature | GPTOne | Diffchecker | DiffNow | Text-Compare | Copyleaks |
|---|---|---|---|---|---|
| Word-level diff for prose | |||||
| Sentence-level diff | |||||
| Detects moved paragraphs | |||||
| Ignores paragraph re-wrapping | |||||
| Original vs AI rewrite mode with change stats | |||||
| Similarity percentage | |||||
| Runs fully in the browser, nothing uploaded | |||||
| Share link with zero server storage | |||||
| No account needed | |||||
| One-click AI detection on either version |
Based on each tool's public product page, September 2026. Grey means partial or not stated.
Most online diff tools answer one question: which lines are different? That is the right question for source code, where a line is a unit of meaning. It is the wrong question for an essay, where a single re-wrapped paragraph changes every line and a moved section looks like a rewrite. The GPTOne diff checker compares paragraphs first, then looks inside the paragraphs that actually changed at word or sentence level. The result is a text difference checker that shows you the edit, not the formatting.
Paste a draft and a final, two student submissions, two versions of a contract clause, or an article and its republished copy. Common passages stay unhighlighted so your eye goes straight to what changed, and the similarity percentage tells you in one number how much of the text is shared. The document comparison runs in your browser, so confidential material never leaves your device.
AI editors rewrite more than they admit. Switch to Original vs AI rewrite mode, paste your own draft beside the AI version, and the diff shows every swapped word and every rewritten sentence, with counts. If the AI touched most of the text, one click sends the rewritten version to the free AI detector so you can see how it scores before you submit or publish. Documents with images can go through the AI image detector the same way.
The diff checker is free to use without an account. There is no server-side limit because there is no server in the loop; each side accepts up to 200,000 characters. Share a comparison with a link that carries the texts itself, or copy a plain-text report into an email or a learning management system. If you also want word counts and reading time for either version, the free word counter works the same way.
Fix grammar and spelling mistakes, detect AI plagiarism, check for plagiarism, generate citations, advanced word counter, powerful summarizer and grammar checker
How to compare two texts online, what the highlights mean, and how this differs from a code diff tool.
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