Compare Text and Code Online

Paste two versions, hit compare, and see exactly what changed — line by line, with syntax highlighting for 20+ languages. Everything runs inside your browser: no upload, no account, no limits.

Loads in a second — about 1.5 MB, then works offline.

What it compares

Plain text, source code, configuration files, JSON, CSV, and Word or Excel documents. Drop two files in, or paste the text directly — the tool detects the language and highlights it accordingly.

How the comparison works

Differences are computed by line, by word, or by character, whichever you pick. Unchanged blocks can be collapsed so long files stay readable, and the split view keeps both versions aligned as you scroll. The comparison itself happens in your browser — the texts are never sent to a server.

Prefer it without the tab?

The same tool exists as a Chrome extension. It opens in one click from the toolbar, works fully offline, and adds something this page cannot do: comparing the source of two open browser tabs.

Get the Chrome extension — free