Free Online Text Diff Checker and Compare Tool
Compare two texts line by line and word by word. Runs entirely in your browser.
Everything runs locally, so no text ever leaves your device. Lines are aligned with the Myers diff algorithm, and paired changes get an extra word-level highlight so you can spot the exact edit. Options such as ignoring whitespace or case only affect matching — the text is always shown as you pasted it.
Features
Line by line and word by word
Lines are aligned with the Myers diff algorithm, and every paired change gets an extra word-level highlight, so you see not just that a line changed but exactly which words inside it did.
Side by side and unified views
Switch between a two-column view that shows removals and additions opposite each other, and a unified view with - and + prefixes that you can copy straight out as a patch-style diff.
Comparison options that match your data
Ignore whitespace, ignore case, trim trailing spaces, and ignore blank lines. These switches only affect how lines are matched — the text itself is always displayed exactly as you pasted it.
Change counts at a glance
The toolbar reports how many lines were added, removed, modified and left unchanged, so you can judge the size of an edit before reading through it.
Only changes, with collapsible gaps
Turn on Only changes to hide long stretches of identical text. Three unchanged lines stay visible on each side of a change and the rest collapses into one clickable row.
Frequently asked questions
Is this text diff tool free to use?
Yes. It is free online with no account, no watermark and no usage limits. Open the page and paste your two texts to see the differences.
How do I compare two texts?
Paste the original text into the left box and the new text into the right box. The diff recomputes as you type, so results appear immediately without pressing a button.
Are my texts uploaded to a server?
No. The comparison runs entirely in your browser. Neither the text you paste nor the diff result is uploaded, and nothing is stored between visits.
What does the Only changes option do?
It collapses blocks of unchanged lines. Three unchanged lines are kept above and below each change, and the hidden remainder becomes a row you can click to expand again.
How do I ignore differences in whitespace or capitalisation?
Turn on Ignore whitespace, Ignore case, Trim trailing spaces or Ignore blank lines. Matching then treats those differences as equal, while the displayed text keeps its original spelling and spacing.
Is there a limit on how much text I can compare?
Each side is capped at 5000 lines. If your input is longer, only the first 5000 lines of each side are compared and the page shows a notice saying so, rather than silently dropping the rest.
Can I copy the diff to use elsewhere?
Yes. The Copy diff button puts the unified diff on your clipboard using standard - and + prefixes, ready to paste into a pull request, a message or a patch file.
