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Text Tools

Text Diff Checker

Compare two texts line by line and see added and removed lines highlighted, with a change count.

+1 −1

The quick brown fox
jumps over the lazy dog
leaps over the lazy dog
The end

How to use it

  1. Paste the original The first version of your text.
  2. Paste the changed version The second version to compare.
  3. Read the diff Added and removed lines are highlighted.

Examples

1 line changed +1 −1
identical no changes

About this tool

Spotting what changed between two versions of some text is tedious by eye. This diff checker lines the two up and highlights exactly which lines were added and which were removed, with a running count of each.

It uses the same longest-common-subsequence approach as developer diff tools, so unchanged lines stay aligned and only real differences stand out. Everything runs in your browser, making it safe for private documents.

Frequently asked questions

How does the comparison work?

It uses a longest-common-subsequence algorithm to line up the unchanged lines, then marks the rest as added or removed — the same approach as code diff tools.

Is my text uploaded?

No. The comparison runs entirely in your browser, so you can safely diff private or sensitive text.

Related tools

Find and Replace Text Paste text, set a search and replacement, and swap every match — with case, whole-word and regex options. Remove Duplicate Lines Paste a list to remove repeated lines, keeping the first of each, with a count of how many were removed. Word Counter Paste your text to see live word, character, sentence and paragraph counts — plus an estimated reading time. Case Converter Paste text and instantly see it in every common letter case, each with a one-click copy button. Slug Generator Convert a title into a lowercase, hyphenated URL slug, with a choice of separator. Word Frequency Counter Paste text to rank the most common words with their counts and share of the total.

Updated June 15, 2026