Grab the annotated diff as text, or save it as a file — instantly, on your device.
About this tool
This text diff checker compares your two inputs one line at a time using a classic
longest-common-subsequence (LCS) algorithm — the same idea behind the
diff command and version-control tools. It finds the largest set of lines that
appear in both versions in the same order, then marks whatever is left as
added or removed. It's handy for reviewing edits to
documents, comparing config files, spotting changes in copied lists, or checking what a
teammate altered.
🔒Private by design. Your text never leaves your device — the comparison happens
right here in your browser, with no uploads and no accounts.
Frequently Asked Questions
How does the diff compare my two texts?▼
It compares them one line at a time, finding the lines that appear in both versions in the same order and marking everything else as added or removed.
What do the colours mean?▼
Lines added in the new version are highlighted green, lines removed from the original are red, and unchanged lines stay plain. A running count of each is shown above the result.
Can I ignore case or spacing differences?▼
Yes. Tick Ignore case so "Cat" and "cat" count as the same, and Ignore leading/trailing spaces so stray indentation doesn't show up as a change.
What is a text diff useful for?▼
Reviewing edits to documents, comparing config files, spotting changes in copied lists, or checking exactly what a teammate altered.
Can I copy or download the differences?▼
Yes — copy the annotated diff as text, or download it as a plain text file.
Is my text uploaded anywhere?▼
No. The comparison happens entirely in your browser on your own device — with no uploads and no accounts.