Runs in your browser · nothing is uploaded
Text Compare
Paste or open two versions of a document, code or JSON to see exactly what changed — line by line, with changed words highlighted.
Differences
Comparisons run in your browser in a background worker — nothing you paste or open is uploaded. Up to 5 MB per side.
Reading the results
Removed
Red lines exist only on the left. In the unified view they start with −.
Added
Green lines exist only on the right. In the unified view they start with +.
Modified
A line changed in place: both versions appear on one row, with the changed words or characters highlighted.
Unchanged stretches are folded, keeping three lines of context around each change. Use the arrows to jump between changes, or “Show unchanged lines” to see everything.
Frequently asked questions
How do I compare two text files?+
Click “Open file” on each side, or drop a file onto the box, or paste text. Differences appear straight away, side by side, with changed words highlighted. Files are read in your browser and never uploaded.
Can it ignore whitespace and capital letters?+
Yes. Choose “Ignore trailing spaces” or “Ignore all whitespace”, and tick “Ignore case”. Lines that only differ in those ways are treated as the same, but the original text is still shown.
Why do two files look the same but show every line changed?+
Usually line endings: Windows uses CRLF and macOS and Linux use LF. “Treat CRLF and LF as the same” is on by default; turn it off to see line-ending differences.
How does JSON comparison work?+
Both sides are parsed and compared value by value, so formatting and spacing don't matter. You get a list of paths that changed — like $.items[2].price — and a line view of both documents neatly formatted. Object key order can be ignored; array order always matters. Invalid JSON is reported with the line and column of the problem.
What is a unified diff?+
The standard text format for changes, used by Git and patch tools: lines starting with − were removed and lines starting with + were added, with a few unchanged lines around each change for context. Download it as a .diff file or copy it.
Is there a size limit?+
Each side can be up to 5 MB. Comparisons run in a background worker so the page stays responsive, and a long comparison can be cancelled.
Is my text uploaded or stored?+
No. Everything is compared in your browser, nothing is sent to a server, and nothing is saved when you close the page. Exported reports are created on your device.