Text Compare

This tool compares line by line, not word by word - so a line with even one character changed shows up as its old version being removed and its new version being added, since the line as a whole is no longer identical. That's still useful for spotting exactly which lines changed, even without word-level highlighting inside the line.

It trims leading and trailing spaces from each line and collapses any run of internal whitespace down to a single space before comparing - so lines that differ only in indentation, trailing spaces, or extra spaces between words are treated as identical.

Yes - the comparison is purely line-based text matching, so it works the same way on source code, configuration files, or any other line-oriented text. It doesn't understand any particular language's syntax, which is exactly what makes it work on all of them equally.

When it's on, each line is lowercased before it's compared to its counterpart, so 'Hello' and 'hello' count as the same line and won't be flagged as a change. The result still displays every line with its original capitalization - only the comparison itself ignores case, not what you see on screen.

The diff algorithm builds a table with one cell for every pair of lines from both texts, so its memory and time cost grow quickly as texts get longer. Once either side passes 2,000 lines, the tool warns you that comparing may take a moment and use noticeable memory, since it all runs in your browser tab rather than on a server - you can still go ahead, it's just a heads-up.