Frequently Asked Questions

Paste your original text in the left pane and the changed text in the right pane. The tool computes the differences using the Longest Common Subsequence (LCS) algorithm and highlights every addition, deletion, and change — updating automatically as you type.

Completely free, with no sign-up, downloads, or limits on how much text you can compare.

Yes. When the Sub-line option is set to Word or Char, the tool highlights the exact words or characters that changed within a modified line — not just that the line changed. Switch to None to see only line-level differences.

There are two view modes. Side by side shows the original and changed text in two aligned columns so you can read both simultaneously. Inline (unified) shows all changes in a single stream with − and + markers for removed and added lines.

Yes. Toggle Ignore case to treat upper and lower case letters as equal. The Whitespace option lets you keep whitespace as-is, trim leading/trailing spaces from each line, or ignore all whitespace entirely — so only meaningful content changes appear.

The summary shows the total count of added lines and deleted lines in the format +N / −M. If both texts are identical, it shows "Identical" instead.

Yes — it works on any plain text, including source code, JSON, YAML, environment files, and other configs. Paste the file contents into each pane and the diff highlights every change.

No. All diffing runs entirely in your browser using JavaScript. Nothing you paste or type is sent anywhere, so your content stays completely private.

It copies a unified diff string to your clipboard — the standard format used by version-control tools like git diff, with − lines for deletions and + lines for additions. You can paste this into a PR description, bug report, or any tool that accepts diff patches.

Yes, the tool is fully responsive. On small screens the two input panes stack vertically and the diff output adapts so there is no horizontal overflow.