Question 1

How does the diff algorithm work?

Accepted Answer

It uses the classic Longest Common Subsequence (LCS) dynamic-programming algorithm to find the minimal set of line insertions and deletions between the two texts — the same fundamental approach used by tools like diff and git diff.

Question 2

What's the difference between side-by-side and unified view?

Accepted Answer

Side-by-side shows the original and changed text in two aligned columns, which is easier to scan visually. Unified view shows a single column with removed lines prefixed with - and added lines prefixed with +, which is easier to copy/paste as a patch-style diff.

Question 3

Is there a size limit?

Accepted Answer

Comparison is truncated to the first 2000 lines per side to keep the browser responsive — you'll see a warning if either input exceeds that.

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