See a line-by-line diff between two versions of a short, generic code example.
This tool compares two blocks of text line by line and highlights what was added, removed, or left unchanged — the same idea as a code diff, run entirely in your browser with no text sent anywhere.
It is useful for comparing two versions of a config file, checking what changed between drafts of a document, or spotting a small edit buried in a large block of text that would be tedious to review by eye.
The comparison is line-based using a longest-common-subsequence approach, so it works best on text that is naturally split into lines (code, lists, paragraphs with line breaks) rather than a single unbroken paragraph, where it will treat the whole thing as one line.
Worked example: comparing "Line one / Line two / Line three" against "Line one / Line TWO changed / Line three" (three lines each) shows "Line one" and "Line three" as unchanged, since they're identical in both, while "Line two" is flagged as removed and "Line TWO changed" as added — even though only one word changed, the line-based approach treats the entire line as replaced rather than trying to highlight the specific word that differs within it. That's the tradeoff of comparing whole lines: simpler and more reliable across many kinds of text, but less granular than a word-level or character-level diff would be.
Line by line. For best results, make sure each logical unit (a sentence, a config entry, a line of code) is on its own line in both boxes.
No — the comparison runs entirely in JavaScript in your browser using a standard diff algorithm. Neither block of text is sent to a server, which matters if you’re comparing something sensitive like a contract draft or a config file with credentials in it.
This version accepts pasted text only. Copy the contents of each file into the two boxes.