Compare two texts online free
Paste two versions of anything and see exactly which lines were added, removed or left alone.
Runs entirely in your browser. Neither version is ever uploaded.
The line-by-line comparison appears here.
How to use the text diff checker
- Paste the earlier version into the left box and the newer one into the right. Order matters: additions are judged relative to whatever is on the left.
- Decide on the two options. Ignoring leading and trailing spaces is on by default and stops indentation changes from flooding the result. Turn on case-insensitive matching when a capitalisation pass is not what you are looking for.
- Press Compare texts. The three counters tell you the scale of the change at a glance, and the panel below shows every line marked as added, removed or unchanged.
- Scroll the result to read the changes in context. Removed lines are struck through in red, added lines are highlighted in green, and untouched lines stay plain so your eye skips them.
What you can use it for
Editors and writers use it to see what a round of feedback actually changed. A collaborator returns a 2,000-word draft claiming they "tweaked a few things" — the diff shows whether that was four sentences or forty, and precisely which paragraphs were rewritten.
It settles contract and policy questions quickly. Paste last year's terms beside this year's and the changed clauses surface immediately, instead of reading twelve pages twice hoping to spot the difference.
Developers who cannot get to a git diff still need one. Two versions of a config file, a CSS block before and after a plugin update, an .htaccess file that worked yesterday — paste both and the offending line is usually obvious within seconds.
It is also a plagiarism sanity check between two specific documents. If a writer submits something suspiciously close to a page you already published, comparing them shows how much is genuinely identical rather than how much merely feels familiar.
Things to know
The comparison works on whole lines, not individual words. A single changed word marks the entire line as removed and re-added. That keeps the output readable on prose, where word-level highlighting turns into confetti, but it does mean a one-character typo fix looks the same as a rewritten sentence.
Prose pasted from a word processor often arrives as one enormous line per paragraph. That still works, but each edited paragraph shows as a full removal and addition. If you want finer detail, break the text at sentence level before pasting.
The algorithm is a longest-common-subsequence diff, the same approach used by version control systems. Moved blocks appear as a removal in one place and an addition in another rather than as a single move, which is standard behaviour for this kind of comparison.
Both panels are capped at around 5,000 lines each for responsiveness. Beyond that the browser can stall for several seconds while it works. If you are comparing something enormous, split it into sections and compare them in turn.
Frequently asked questions
Not directly — it takes plain text. Open the document, select all, copy, and paste into the box. Formatting, fonts and images are dropped, which is usually what you want, since the comparison is about the words rather than the styling.
Because the comparison is line based, and a pasted paragraph is a single line. Every change inside it marks the whole line. Splitting your text so each sentence sits on its own line gives you much more precise results.
There is no export button, but the result is ordinary selectable text on the page. Select the panel, copy, and paste it into a document or email. Printing the page also works and keeps the colour coding.
No. Both boxes are read directly by JavaScript running in your tab and the comparison happens in your device's memory. Nothing is transmitted, which is why this is safe to use on unpublished contracts and internal documents.
It trims whitespace from both ends of every line before comparing. Two lines that differ only by indentation or a stray trailing space are then treated as identical. The lines are still displayed exactly as you pasted them.