ToolStack

Diff Checker

Compare two blocks of text line by line and see exactly what was added, removed or left unchanged.

100% private — everything runs in your browser

How to Use

  1. 1

    Paste the original text in the left panel.

  2. 2

    Paste the modified version in the right panel — the diff updates as you type.

  3. 3

    Turn on “Ignore whitespace” when indentation changes should not count as edits.

  4. 4

    Copy the +/- change list with the copy button.

Examples

Single line change

Input

Version A: “price = 10”
Version B: “price = 12”

Output

-price = 10
+price = 12

Added paragraph

Input

The second text ends with one extra line

Output

+A new closing paragraph appears as one added line

FAQ

How does the comparison work?

Both texts are split into lines and aligned with a longest-common-subsequence algorithm, so an inserted or deleted line does not shift every line below it.

Are very large texts supported?

Up to 1500 lines per side are compared. Longer input is truncated and a notice is shown above the diff.

Is my text uploaded anywhere?

No. The comparison runs entirely in your browser.

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