Web Tools

Text Diff Viewer

Compare two blocks of text and see a line-by-line diff with additions and deletions highlighted. Runs a longest-common-subsequence diff entirely in your browser — nothing is uploaded.

diff compare text merge developer-tools

Published May 25, 2026

All interactive tools run entirely in your browser. Your data never leaves your device.

How It Works

Paste your original text on the left and the changed text on the right. The tool runs a longest-common-subsequence (LCS) line diff and renders a unified view: removed lines are prefixed with - and tinted red, added lines with + and tinted green, and unchanged lines stay muted for context. A running tally shows how many lines were added and removed.

Features

Line-level diff: classic LCS algorithm, the same approach Git uses for line matching
Unified view: additions, deletions, and context in a single readable column
Stats: at-a-glance count of added and removed lines
Private: the comparison runs locally — neither side of your text is uploaded

Use Cases

Spotting what changed between two versions of a config file or snippet
Reviewing edits to a block of copy before committing
Comparing API responses or log output side by side