Text diff

• Code review — paste old and new versions of a function to see exactly what changed.
• Config audits — diff nginx.conf from staging vs production.
• Prose editing — compare draft revisions of a blog post or contract.
• Translation review — line up source and translated strings.

• Green + on the right side — line added in B.
• Red - on the left side — line removed from A.
• Both sides shown together — line modified (matched delete + insert).
• Both sides equal — unchanged line. Line numbers in each side reflect that side's actual line.

• Whitespace matters — trailing spaces and inconsistent indenting will show. Normalise first if you want to ignore them.
• Long lines — wrap or scroll horizontally. The diff doesn't break long lines apart.
• Performance — the LCS DP is O(n × m). Inputs over ~5,000 lines per side may slow your browser.
• Word-level highlights — not shown. We mark only "this whole line changed". For mid-line precision, copy the changed lines into the string-diff tool.

When to reach for it. Use it to spot what changed between two versions of text — edits, insertions and deletions — line by line.

When something else is better. It compares characters, not meaning; reordered-but-equivalent text still shows as changed.

The pitfall to watch. Invisible differences (trailing spaces, tabs vs spaces, CRLF vs LF line endings) often explain a diff that “looks identical.”

Everything runs on your device. The values you enter are processed locally in this browser tab — EpitomeTool does not send your input to a server, store it, or log it. That means you can use the tool offline once the page has loaded, and refreshing the tab wipes the slate.