True word-level highlighting
When a line is edited rather than replaced, you see the individual words that were removed and added inside that line — not a whole red-and-green block you have to re-read yourself.
Free online diff tool
Text Compare — Online Diff Checker for Two Texts
Paste two versions of any text and see exactly what changed — word by word and line by line. Side‑by‑side or unified view, a similarity score, and a clean export. Everything runs in your browser, so nothing you paste is ever uploaded.
- 100% private — nothing leaves your device
- Instant word-level results
- No sign-up, no limits, no ads in the tool
Comparison result
Similarity
0%
Lines added
0
Lines removed
0
Lines modified
0
Lines unchanged
0
Why this text comparison tool beats the usual diff checker
Most online compare-text tools stop at line highlighting. This one shows the exact words that moved, scores how similar the two versions really are, and keeps every character on your own machine.
Similarity score you can quote
A percentage match plus counts of added, removed, modified and untouched lines. Useful for edit reviews, plagiarism spot-checks, translation QA and contract redlines.
Nothing is uploaded
The comparison runs entirely in JavaScript inside your browser. No server round-trip, no stored history, no account. Safe for legal drafts, source code and client documents.
Split and unified views
Read changes side by side like a review tool, or switch to a unified patch-style list that is easy to copy into a ticket, a pull request comment or an email.
Noise filters that matter
Ignore case, collapse whitespace or strip punctuation so reformatting, indentation changes and smart quotes stop drowning out the edits you actually care about.
Built for phones too
The panes stack, the diff scrolls cleanly and the buttons stay thumb-sized. Comparing two paragraphs on a phone works as well as it does on a wide monitor.
How to compare two texts online
Four steps, no setup. The comparison starts the moment both boxes have content.
Paste the original
Drop the earlier version of your document, paragraph, list or code into the left box. Any length works — a sentence or several thousand lines.
Paste the new version
Put the edited version in the right box. If you pasted them the wrong way round, hit Swap instead of re-pasting.
Tune what counts as a change
Switch between word, character and line granularity, and turn on the ignore options if formatting differences are creating false positives.
Read, copy or export
Scan the highlighted result, check the similarity score, then copy the unified diff or download it as a text file for your records.
Who uses a text difference checker
Anywhere two versions of the same thing need to be reconciled quickly and accurately.
Writers and editors
See precisely which sentences an editor rewrote before you accept a round of changes.
Developers
Diff config files, JSON payloads, logs or query results without leaving the browser or spinning up a repo.
Legal and contract teams
Spot silent clause edits between two drafts — locally, so confidential wording never touches a third-party server.
Students and researchers
Check how much a rewritten passage still overlaps with the source before submitting.
Translators and localisers
Compare an updated source string set against the previous release to find exactly what needs re-translating.
Support and ops
Diff two error logs or two environment files to isolate the one line that broke a deployment.
Understanding your comparison results
A diff checker does not simply line up text top to bottom. It looks for the longest sequence the two versions still share, treats that as the anchor, and reports everything else as an insertion or a deletion. That is why moving a paragraph shows up as a removal in one place and an addition in another rather than as a mysterious cascade of changes further down.
Word, character or line granularity
- Word is the default and the right choice for prose, documentation and most content edits. It highlights whole words, which reads naturally.
- Character is stricter and useful for codes, IDs, hashes, URLs and anything where a single transposed digit matters.
- Line only skips inner highlighting entirely and reports whole lines as changed — the fastest mode for very large inputs.
How the similarity percentage is calculated
The score compares the two texts at word level and reports twice the shared-word count divided by the combined word count. Two identical texts score 100%. Two texts with nothing in common score 0%. It is a readable measure of overlap, not a plagiarism verdict — a rewritten passage that keeps the same argument can still score low.
When to switch on the ignore options
Turn on ignore whitespace when one version was reflowed, re-indented or pasted from a PDF. Use ignore case when a style change swapped headings to sentence case. Ignore punctuation is best kept for translation and transcription work, where smart quotes, dashes and trailing periods differ but the wording does not.
Once you have the changes you need, tools like our word counter, case converter and JSON formatter handle the cleanup that usually comes next.
Text compare FAQ
Common questions about comparing two texts online.
How do I compare two texts and find the difference?
Paste the earlier version into the left box and the newer version into the right box. The comparison runs automatically and highlights removed words in red on the left and added words in green on the right. You can also press Compare text to re-run it after changing the options.
Is this text compare tool free and does it need an account?
It is completely free with no sign-up, no character cap and no daily limit. There is no paid tier gating the side-by-side view, the export or the similarity score.
Is my text uploaded to a server?
No. The entire diff is computed in your browser with JavaScript. Your text is never transmitted, logged or stored, which makes the tool safe for contracts, medical notes, source code and other confidential material. You can even disconnect from the internet after the page loads and it will still work.
What is the difference between word, character and line comparison?
Word comparison highlights whole words and reads most naturally for prose. Character comparison flags every individual character that changed, which is better for IDs, hashes and numbers. Line-only comparison marks entire lines as changed without inner highlighting and is the fastest option for very large documents.
How is the similarity percentage calculated?
It uses word-level overlap: twice the number of words the two texts share in sequence, divided by the total word count of both texts. Identical texts return 100%. It is a measure of textual overlap and should not be read as a formal plagiarism score.
Can I compare code, JSON or CSV with it?
Yes. The tool is language-agnostic and preserves indentation, so it works for source code, JSON, YAML, CSV rows, SQL and log files. For JSON specifically, format both sides first so key ordering and indentation do not create noise.
How large a document can I compare?
Documents up to a few thousand lines compare almost instantly. Beyond that the tool automatically falls back to a faster line-level strategy and tells you it has done so, so the page never freezes.
Can I save or share the comparison?
Use Copy diff to put a unified, patch-style version of the changes on your clipboard, or Download to save it as a .txt file. Both include the line numbers and plus/minus markers, so the result stays readable in an email, a ticket or a code review.
Stop re-reading two drafts line by line
Paste both versions, read the highlights, and move on. Free, private, unlimited — and it works just as well on a phone as it does on a desktop.
Runs entirely in your browser · no text is uploaded, stored or shared.