Text Diff Checker
Compare two texts side-by-side and highlight differences.
Enter text in both fields, then click Compare to see differences
Press Cmd/Ctrl+Enter to compare quickly
About the Text Diff Checker
Compare two blocks of text and see exactly what changed, line by line. Useful for spotting the difference between two config files, two API responses, or two versions of a document when you do not have them in version control side by side.
How to use it
- 1 Paste the original text into the left panel.
- 2 Paste the changed version into the right panel.
- 3 Differences highlight automatically — additions in green, removals in red.
- 4 Scroll through to review every change in context.
What it does
- Side-by-side comparison with synchronised scrolling
- Line-level addition, removal and modification highlighting
- Change count summary
- Handles large documents entirely in the browser
Frequently asked questions
Is my text sent to a server?
No. Every calculation happens locally in your browser using JavaScript. Nothing you paste is uploaded, logged, or stored on a server, which makes the tool safe to use with production data, credentials, and customer records.
Can it compare two files?
Yes — open each file, copy its contents into the corresponding panel, and the comparison runs immediately. Nothing is uploaded, so comparing files with sensitive contents is safe.
Does whitespace count as a difference?
Yes. Trailing spaces, changed indentation, and different line endings all register as changes. That is intentional — invisible whitespace differences are exactly the kind of thing that breaks a build, so hiding them would defeat the purpose.
What is the difference between a unified and a split diff?
A split (side-by-side) diff shows both versions in parallel columns, which is easier for reviewing prose and reformatted code. A unified diff interleaves them into one column with +/- markers, which is the format git uses and what patch files contain.