Compare two texts side by side and see every added and removed line
Runs in your browser. Nothing you type is sent anywhere. Updated on 24 Oct 2026.Comparing two texts shows every line added, removed or changed, side by side. Useful for two versions of a contract, a config file, or an essay a colleague edited. A 5,000 line file compares instantly, and neither version is uploaded, so drafts stay private.
Paste the contents of the old file into Original and the new file into Changed.
Choose Lines, Words or Characters, and Side by side or Unified.
Turn on Ignore whitespace or Ignore case to skip differences that do not matter.
Read the added and removed counts, then click Copy unified diff or Download .diff.
This diff checker compares two texts and marks exactly what changed: lines that were removed, lines that were added, and inside a changed line, the words that differ. A count at the top shows how many lines, words or characters were added and removed, so you know the size of a change before you read it.
Developers paste two versions of a config file or an SQL migration to review a change without a Git repository. Writers and editors compare a contract clause before and after a round of comments, or check which prices changed between two product lists copied from a spreadsheet.
Choose line mode for code and lists, word mode for prose, and character mode for short strings such as IDs or keys where a single character matters. Ignore whitespace skips changes in indentation and spacing, and ignore case treats "Total" and "total" as the same. Line endings from Windows and Mac are normalised, so a file saved on another system does not show every line as changed.
Everything runs in your browser; neither text is uploaded, which makes it safe for code, credentials and customer data. Texts up to 2 MB together compare in about a second on a normal laptop.
Switch between side-by-side and unified views, swap the two sides with one click, and copy the result as a unified patch that git apply and patch understand. Related tools: Regex Tester, JSON Formatter.
Yes. There is no signup, no cap on the number of comparisons and no watermark on anything you copy. Two texts of up to 2 MB together can be compared in one go, which covers most source files, contracts and exported lists of records.
No. The comparison is computed in your browser and neither text leaves your device, so source code, contracts, medical notes and files holding personal data can be compared safely. No account is needed, and there is no limit on how many comparisons you run.
Paste the texts, then turn on Ignore whitespace. Lines that differ only in indentation, repeated spaces or trailing spaces are then treated as the same, and only real changes are marked.
Line mode marks whole lines and suits code and lists. Word mode marks individual words and suits paragraphs of prose. Character mode marks single characters and suits short strings such as IDs, hashes or keys.
Yes. Copy unified diff writes the standard unified format, with three lines of context around each change and the usual @@ headers, which git apply and the patch command both accept. Paste it into a pull request comment, or save it as a .patch file to apply elsewhere.
Usually the two texts differ in indentation or trailing spaces on every line, which line mode counts as a change. Turn on Ignore whitespace, and Ignore case if only capitalisation differs. Windows and Mac line endings are normalised already, so CRLF against LF is never the cause.
Still stuck? Ask about Diff Checker and anybody who knows can answer. No account needed.
Also works as: Text Compare · Compare Two Texts.
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In the collection Debug and Inspect.