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Text Diff Checker

Compare two texts side by side and highlight what was added or removed.

  • Free
  • Real-time
  • Runs locally
Ln 1, Col 1
Ln 1, Col 1

Compare options

Compare by

View

Added

0

lines

Removed

0

lines

Modified

0

lines

Similarity

100%

Differences

Paste two versions of a text above to see what changed.

Paste an original and a changed version of any text to see every difference at a glance. Added lines are highlighted in green, removed lines in red, and inside modified lines the exact words that changed are marked, so you never have to compare two documents by eye again.

Compare contracts, essays, code, configuration files or lists, side by side or in a unified view. You can ignore case and whitespace, hide unchanged lines, compare by words or characters, and export the result as a .diff file. Both texts stay in your browser.

01

How to compare two texts

  1. STEP 01

    Paste both versions

    Put the original text on the left and the changed text on the right. The comparison updates as you type.

  2. STEP 02

    Choose how to compare

    Compare by lines, words or characters, pick side-by-side or unified view, and ignore case or whitespace if needed.

  3. STEP 03

    Review and export

    Check the highlighted changes and similarity score, then copy the diff or download it as a .diff file.

02

Features

  • Line and word highlights

    Changed lines are paired up and the exact words that differ inside them are highlighted.

  • Side by side or unified

    View the two versions in aligned columns, or as a single list of removed and added lines.

  • Word and character modes

    Compare prose word by word or character by character in a track-changes style view.

  • Ignore case and whitespace

    Skip differences in letter case, indentation or extra spaces that do not matter to you.

  • Focus on what changed

    Hide unchanged lines and keep just enough context around each change.

  • Export as .diff

    Copy or download a unified diff with + and − lines, ready to share or archive.

03

How the comparison works

The checker uses the Myers diff algorithm, the same approach used by tools like Git, to find the smallest set of additions and removals that turns the original text into the changed one.

  • Lines that only exist in the original are shown as removed; lines only in the changed text are shown as added.
  • When a removed line and an added line sit in the same place, they are shown as one modified line with word-level highlights.
  • Similarity is the share of lines (or words and characters) that are unchanged across both texts.
  • Windows and Unix line endings are treated as the same, so files from different systems compare cleanly.
04

Frequently asked questions

How do I compare two texts for differences?

Paste the original text in the left box and the new version in the right box. Differences appear immediately below, with removed text in red and added text in green.

Can I compare code or configuration files?

Yes. Line mode with the unified view works like a code diff. Turn on “Ignore whitespace” if you only changed indentation, and download the result as a .diff file.

What does the similarity percentage mean?

It is the share of content that is the same in both texts. 100% means the texts are identical; 0% means nothing matches.

Why are some changes shown as a removed line plus an added line?

When text is rewritten heavily or moved, there is no clear one-to-one match, so the old lines are shown as removed and the new ones as added. Lightly edited lines are shown as modified with word highlights.

Is there a size limit?

There is no fixed limit. Large files with a few changes are compared quickly; for extremely different large texts, the middle section may be shown as fully replaced to keep your browser responsive.

Are my texts uploaded?

No. Both texts are compared in your browser, which makes the tool safe for confidential documents.

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