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Text diff

Compare two pastes line by line and mark lines that were removed from the left or added on the right.

The answer

A line that appears in both texts is unchanged. A line only on the left is removed. A line only on the right is added. The comparison is the whole line, not a character inside it.

Result

Line diff

  alpha
- beta
+ gamma

Lines only on the left

1

Lines only on the right

1

What do you want to do next?

How this works

Both texts are split on line breaks. A longest-common-subsequence pass keeps shared lines in order and reports the lines that are not shared.

The result marks an unchanged line with a leading space, a removal with a minus, and an addition with a plus. Each side is limited to 400 lines.

Practical steps

  1. 1

    Paste the older text on the left and the newer text on the right.

  2. 2

    Read minus lines as removals and plus lines as additions.

  3. 3

    If a single word changed, the whole line is reported as removed and added.

Examples

  • Left “alpha / beta”, right “alpha / gamma”

    alpha is unchanged, beta is removed, and gamma is added.

Common mistakes

  • ×

    Expecting a highlighted word when the tool is comparing whole lines.

Frequently asked questions

Does this ignore spaces?

No. A trailing space makes the line different.

Can I compare more than two texts?

No. This page compares one pair.

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