Text Diff

Line-level diff between two texts (LCS algorithm, unified view)

Compare two pieces of text line-by-line. The LCS algorithm finds the minimal set of additions and removals to transform left into right. Matching lines are kept; additions appear in green, removals in red.

Left (original)

Right (modified)

Ignore whitespace

Ignore case

Trim lines

+ 2 added

− 1 removed

3 kept

Unified diff

11  Hello world
2- This is line 2
2+ This is line 2 modified
33  The quick brown fox
4+ Inserted line
45  Last line

How to use

Paste the original text into the left panel and the modified text into the right panel.
Toggle options to ignore whitespace, ignore case, or trim lines before comparing.
Read the unified diff view: lines prefixed with + are additions, - are removals, and unmarked lines are unchanged.
Check the stats bar for the total count of added and removed lines.
All diffing runs entirely in your browser — nothing is sent anywhere.

Examples

Pasting "hello world" on the left and "hello earth" on the right shows one removed line and one added line with the changed word highlighted.
Enabling ignore-case means "Hello" and "hello" are treated as identical and produce no diff output.

Verify outputs before using in production. No warranty — see Terms.