Compare sensitive files without uploading them

The job to be done

Keep confidential files on the computer that holds them.

Contracts, customer exports, credentials, payroll sheets, and unreleased source code often need the most careful comparison, and they are also the files a company policy says must not be pasted into a website. An online diff checker only works after you hand a copy to a service you do not control.

Diff Anything is a desktop app for macOS and Windows. It reads the files you open from your own disk and compares them on that computer, with no account to create. Its only outside connection is to your platform's app store, for the Pro price, a purchase, or the Pro entitlement check.

Recommended path

Compare, review, and share only what you choose.

The same steps apply whether the pair is code, configuration, a spreadsheet, or a document.

1. Open files or paste text

   Choose files from disk, drop them onto the window, or paste content into either side. Auto selects a mode for the content, and the toolbar lets you pick a different one.

2. Review code and text in place

   Source files open with syntax highlighting. Switch between Smart and Line to see token-level or line-level changes, and turn on Editable to correct the text during the review.

3. Keep secrets masked

   Environment files show which variables differ while their values stay hidden. Use Reveal value on a single cell when you need to check one value.

4. Decide what is stored

   With Pro, comparisons of two files on disk go into local history. To keep file contents out of it, clear Keep small text snapshots so history can reopen them in Settings; Clear Unpinned History deletes every entry you have not pinned.

5. Share a report instead of the files

   With Pro, export a Self-contained HTML, JSON report, or Markdown review report to a folder you pick. Tick Include only differences marked reviewed, and leave Redact environment values on for .env comparisons.

Capabilities involved

The parts of Diff Anything that keep a sensitive review local.

Limits to know

What local comparison covers.

Local comparison keeps the content away from third-party services, not from people or software with access to your computer. Source files, exported reports, and Pro history are as protected as the device and folders that hold them.

History snapshots keep file text for sources within the Maximum saved snapshot size setting (1 MB by default); snapshots of environment files keep variable names with every value masked. Only comparisons of two files on disk are added to history; pasted text is not.

A saved profile records the paths of the files it compares and the full text of any side that was pasted. Save profiles from files on disk if the text itself should not be stored.

Free covers all comparison modes, with a 5 MB limit per file and 10 comparisons a day. History, saved profiles, and report export need Pro.

Related manual

Privacy, safety, and troubleshooting

Understand the local comparison boundary, recover from input and copy problems, and prepare useful diagnostics without exposing sensitive sources.

Its sections cover what stays local, handle sensitive values, resolve parser and mode errors, recover folder synchronization, explain unexpected results, reset only what is necessary. Use it when you are ready to reproduce this workflow with your own project data.

Direct answers

Questions about this use case.