Text Diff Checker
Compare two blocks of text line by line and see what was added, removed, or unchanged.
How this tool works
Paste both versions
Text A goes in the left panel, Text B in the right.
Lines are compared automatically
A line-based diff runs as soon as both fields have content.
Read the highlighted result
Added lines show green with a left border, removed lines show red, unchanged lines stay plain.
Check the summary counts
A quick tally of lines added and removed sits below the diff for an at-a-glance summary.
Quick facts
- Category
- Text Tools
- Best for
- Spotting exactly what changed between two drafts
About this tool
Paste two versions of a text into the Text A and Text B panels to see a line-by-line comparison, with added lines highlighted green and a left border, removed lines highlighted red with their own border, and unchanged lines shown plain in between. The comparison uses a straightforward longest-common-subsequence line matcher rather than a full Myers diff implementation - it’s tuned for clarity on typical-sized text (a paragraph, a config file, a changelog entry) rather than optimal minimal-diff output on huge files, so it’s a quick way to spot what actually changed between two drafts, not a replacement for a dedicated diff tool in your version control system. Everything runs client-side, so neither text is ever uploaded.
Why use this tool
Instant visual highlighting
Green and red line markers make changes obvious without reading every line manually.
Two-panel side-by-side input
Paste both versions directly rather than uploading files or switching between tabs.
Clear about its limits
Uses a simple line-based comparison, honestly described as not a full Myers diff algorithm.
Nothing leaves your browser
Compare drafts of sensitive documents without either version being uploaded anywhere.
Frequently asked questions
This tool compares whole lines using a simpler longest-common-subsequence approach, so it works well for line-level changes but doesn’t detect word-level or character-level edits within a line the way git’s diff can. If a single word changes in an otherwise identical line, that whole line shows as one removed line and one added line rather than a highlighted word.
Yes - the comparison is order-sensitive, since it’s matching lines by both content and position. If a block of lines gets moved elsewhere in the text without any content change, it will typically show as that block being removed from its old position and added at its new one, rather than being recognized as a move.
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