Compare two blocks of text and highlight every addition, deletion and change — side by side or unified. Free, in your browser.

Paste the original text on the left and the changed text on the right — differences are highlighted instantly. Nothing is uploaded.

Original
Changed
View
Differences
Enter text in both panes to see the differences.

About Diff Checker / Text Compare

The Diff Checker compares two blocks of text and highlights exactly what changed. Paste the original into one pane and the modified version into the other; the tool computes a line-based diff and renders every addition, deletion and changed line, with word-level highlighting available inside changed lines to pinpoint the edit.

Two views cover different habits: a side-by-side layout that mirrors code-review tools, and a unified view like a classic patch. Options let you ignore case differences and ignore whitespace so reformatted code doesn’t drown out real changes, and a summary counts additions, deletions and changed lines at a glance.

A swap button flips the two sides, the result can be copied, and identical inputs are called out explicitly. The comparison runs entirely in your browser, which makes it safe for contracts, config files and unreleased copy — nothing is uploaded.

How to use Diff Checker / Text Compare

  1. Paste the original text into the left pane and the changed version into the right.
  2. Choose the view: side-by-side or unified.
  3. Toggle “Ignore case”, “Ignore whitespace” or word-level highlighting as needed.
  4. Read the highlighted result and the additions/deletions summary.
  5. Use Swap to reverse the comparison, or copy the diff for sharing.

Frequently asked questions

Side-by-side shows the two versions in parallel columns with changes aligned, which is easiest for reviewing. Unified interleaves removed and added lines in one column, the compact format used by patches and version-control tools.

Whenever a reformat — re-indentation, tab-to-space conversion, trailing-space cleanup — would flood the diff with noise. With whitespace ignored, only lines whose actual content differs are flagged, exposing the meaningful edits.

Within each changed line, it marks the specific words that differ instead of flagging the whole line. That is the fastest way to spot a one-word edit inside a long sentence or a renamed variable in a dense line of code.

No. The diff algorithm runs completely in your browser — both texts stay on your machine, so it is safe to compare confidential contracts, credentials-bearing configs or unpublished content.

Yes, free with no length-based paywall or account requirement. Compare as many document pairs as you need.


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