Text Diff

Paste the original text on the left and the changed version on the right. A longest-common-subsequence diff marks each line as added, removed, or unchanged, so real changes stand out even when lines move around. Options let you ignore case differences and trailing whitespace.

Common uses

• Spot what changed between two versions of a document
• Compare configuration files without git
• Verify that an edit only touched the lines it should

Limitations

• The diff is line-based — a small edit inside a long line shows as one removed and one added line

Are the two texts I compare uploaded anywhere?

No. The diff is computed entirely in your browser and neither text is transmitted or stored, so you can compare contracts, configs, or private notes without them leaving your device.

How does a text diff decide which lines changed?

It computes the longest common subsequence of lines between the two versions — the largest set of lines that appear in both in the same order. Everything in that subsequence is marked unchanged; the rest shows as removed from the left or added on the right.

Can the diff highlight which words changed inside a line?

No, comparison is line by line. Editing one word in a long paragraph line shows the whole line as removed plus a new added line; splitting text into shorter lines before comparing makes small edits easier to spot.

How do I ignore capitalization or whitespace differences?

Turn on the ignore-case option to treat "Apple" and "apple" as the same line, and the trailing-whitespace option to ignore spaces at line ends. Leading indentation still counts, so re-indented lines show as changed.