Text Diff Checker
Paste two versions of text side by side and see which lines changed. Additions, deletions, and modifications are highlighted so you can spot differences without reading every line manually.
| Line | Left | Right |
|---|---|---|
| 1 |
This is a simple line-by-line diff (does not try to align moved/inserted blocks). For code diffs, use Git diffs for best results.
How to use
- Paste the original text on the left side and the updated version on the right.
- Differences are highlighted automatically as you type or paste.
- Scroll through the output to see which lines were added, removed, or changed.
Related tools:
A diff compares two versions of text and shows what changed - which lines were added, deleted, or modified. It is the same mechanic that powers version control systems like Git, though this is a simple line-by-line comparison rather than a git diff with context. Paste the original text on the left and the revised version on the right, and the changes are highlighted.
Common use cases: comparing two versions of a document before accepting edits, checking what changed between two config files, verifying that a script produced the expected output, or spotting the difference between two similar-looking code snippets that behave differently. The visual diff is faster than reading both versions carefully.
Frequently Asked Questions
How does a text diff algorithm work?
Most diff algorithms find the longest common subsequence (LCS) between two texts. Lines in both versions that are common stay unchanged. Lines only in the original are marked as deleted. Lines only in the new version are marked as added. This is the Myers diff algorithm used by git and most diff tools.
Can I compare code files with this tool?
Yes. Paste two versions of any text content - code, config files, JSON, prose - and the diff highlights the differences. Syntax highlighting is not included, but the structural differences are clearly shown.
What is the difference between line diff and character diff?
Line diff shows which whole lines changed. Character diff (or word diff) highlights the specific words or characters within a line that differ. For prose and small edits, character diff is more informative. For code with full rewrites, line diff is cleaner.