Diff Checker
Free online diff checker tool. Compare two text blocks side by side and highlight the differences instantly. Shows added, removed, and unchanged lines with color coding. Perfect for developers comparing code, writers reviewing document changes, and anyone who needs to spot differences between two versions of text. All processing runs 100% client-side — your text never leaves your browser.
how to use
- 1.Paste the original text in the left panel
- 2.Paste the new or modified text in the right panel
- 3.Click Compare to see the differences highlighted
- 4.Green lines are additions, red lines are deletions
frequently asked
What does the diff show?
Green highlighted lines are additions (in new text), red lines are deletions (removed from original), and white lines are unchanged.
Can I compare code?
Yes — the diff checker works with any plain text including code, JSON, markdown, and prose.
Is there a size limit?
No hard limit — but very large texts may be slower to process in the browser.