See Which Bytes Changed Between Two Files

TL;DR: Hex Compare is a free online tool that shows the byte-level differences between any two files — hex and ASCII side by side, insertions kept aligned, a change list to step through — right in your browser, no signup, nothing uploaded or transferred.For firmware, exports, save files — anywhere “binary files differ” isn't an answer.

Start Comparing Files…
Screenshot of Hex Compare
Christopher Atlan

Built by Christopher Atlan at Leitmotif GmbH. Making file-comparison tools since 2020 — building software for over 18 years. diff.tools is one idea: a focused tool for each format, with results you can hand from one tool to the next.

A quick tour

  1. An insert is an insert

    Most byte-by-byte tools fall apart the moment a file grows by a few bytes: everything after the insertion “differs.” Here the files are aligned by content — below, 12 inserted bytes show as one small insert, the offsets diverge, and every row after still lines up.

    Two binary files side by side in hex: a 12-byte insertion highlighted at offset 0x400 with the gap hatched on the left file, rows aligned before and after
  2. A change list, not a scavenger hunt

    Every changed region is a card — offset range, the bytes before and after — and clicking one jumps straight there. Or type an offset. The unified view shows both files' offsets in one aligned grid, and the row width switches between 8, 16, and 32 bytes.

    The unified byte view: dual offset columns, the inserted bytes reading 'build-2026px' in the ASCII column, and change cards listing the insert and the replaced bytes
  3. Big files stay smooth

    The comparison runs in a background worker with live progress, and only the rows on screen are rendered — so multi-megabyte files scroll like small ones. Files that turn out to be completely unrelated degrade gracefully to a coarse alignment with an honest badge instead of a hung tab.

How to compare two binary files?

  1. Open the free hex comparison tool — it runs in any current browser, on your device, no signup.

  2. Click Choose File A and pick the first file, then Choose File B for the other one. Any file type works.

  3. Step through the change list, or jump straight to an offset. Side-by-side and unified views keep the byte rows aligned even across insertions.

Frequently asked questions

  1. Does it work with large files?

    Yes. The comparison runs in a background worker with live progress, and the byte grid only renders what’s on screen — multi-megabyte files stay smooth.

  2. Are my files uploaded?

    No. The comparison runs entirely in your browser; file contents never leave your device.

  3. Can it edit bytes?

    No — it’s a comparer, not a hex editor. It shows you what changed; it never touches your files.

  4. Which browsers are supported?

    Any current browser — Chrome, Edge, Firefox, and Safari all work.

Requirements

Any current browser.

Privacy & Data Processing

Privacy and security aren't just something you should hope for — they're something you should expect. Modern browsers allow us to process everything directly on your device, which means we never upload, transfer, or share your files.

Your files stay completely private. All comparisons happen locally in your browser. Your data stays your business.

LeitmotifChristopher Atlan
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The team behind the tool

We're Leitmotif, a small company from the Alps — Carinthia, Austria and Bavaria, Germany. File comparison is what we do all day: we make Kaleidoscope, the Mac diff app, and diff.tools brings that experience to the browser.

We believe professional tools should be beautiful to look at and fun to use, while giving you all the power you need to get the job done. And we respect your files too much to ever upload them — everything here runs on your machine.

Feedback

We're constantly improving our free online hex comparison to make it faster and more accurate. Share your feedback and help us understand what kind of files you compare.

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