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Diff Checker

Compare two snippets side by side with colour-coded additions and deletions.

Private Instant No sign-up No daily limit

Free to use. No account, no daily limit, and no watermark on the result.

 Compare two snippets

Waiting for text
Lines added
0
Lines removed
0
Lines changed
0
Lines unchanged
0
Similarity
0%

Side-by-side comparison

● added ● removed ● changed

Type or paste into both boxes and the comparison appears here instantly.

Everything runs locally in your browser — no text is uploaded or stored.

How to check the differences between two texts

1

Paste the original

Drop the "before" version into the left text area — code, articles, config files or plain notes.

2

Paste the changed version

Put the "after" version on the right. The comparison refreshes automatically as you type.

3

Read the colour-coded rows

Green rows are additions, red rows are removals and amber rows are lines that were modified.

4

Copy the unified diff

Hit "Copy unified diff" to get a standard @@ hunk patch you can paste into a terminal or GitHub pull request.

Diff checker — frequently asked questions

The checker compares the amount of content the two texts share using a character-level commonality score (the Dice coefficient). 100% means the texts are identical, 0% means they share no content at all. A score above 90% usually indicates only a few words changed.

Green marks lines that exist only in the changed text, red marks lines that exist only in the original, and amber marks lines that were edited. Inside an amber row the changed words are marked up with inline insertion and deletion markers so you can see exactly which part moved.

Never. The comparison engine is a local JavaScript library that ships with the page. Your snippets stay inside your browser tab, which makes the tool safe for confidential code, contracts and internal notes.

Yes. The "Copy unified diff" button produces a standard unified patch with ---, +++ and @@ hunk headers. You can paste it into a chat, save it as a .patch file and apply it with git apply.

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