Diff Viewer

When you'd reach for this

Git shows you diffs for files it tracks. Everything else is on you: the config dump from staging versus production, two versions of an API response, the SQL a migration generated last week versus today. Paste both versions here and you get the same colored, line-by-line comparison you'd get in a code review, with added and removed line counts up top so you know instantly whether the texts differ at all — the badge flips between "Identical" and "Changes detected".

How to use it

• Paste text into the Original and Modified panes, or use Load original and Load modified to pull in files. Sample fills both sides with demo content if you just want to poke around.
• Toggle between Split (side by side) and Unified (single column) view.
• Set Granularity to Line, Word, or Char depending on how fine you want the highlighting.
• Check Ignore whitespace to skip indentation-only noise, or Show diff only to hide unchanged regions. The Context field controls how many surrounding lines stay visible.
• Swap flips the two sides. Copy patch and Download give you a unified patch you can apply or attach to a ticket.

Real-world uses

Config drift is the classic one: paste the nginx or Kubernetes config from two environments and see exactly which lines diverged. It's also handy for checking what a formatter or codemod actually changed before you commit it, and for comparing two versions of a prompt, an email template, or a legal paragraph where Word's track changes isn't an option. The Share link button encodes the whole diff into the URL, so you can drop a reproducible comparison straight into Slack.

Frequently asked questions

Does my text get uploaded anywhere?

No. The diff is computed in your browser and nothing is sent to a server. One caveat: a share link puts the text into the URL itself, so only share it with people who should see the content.

Can I compare files instead of pasted text?

Yes — load a file into each side. You can also rename each side in the Original and Modified fields, and those names end up in the exported patch headers.

What happens with huge inputs?

Large diffs switch on safeguards: the granularity and show-diff-only controls are disabled and the summary stats get capped, so the page stays responsive instead of freezing on a massive comparison. You'll see a "large diff safeguards on" note in the summary bar when that kicks in.

What's the difference between Word and Char granularity?

Word highlights changed words inside a line; Char highlights individual characters. Char is the one you want when you're hunting a single-character typo in a long token or URL.