Open a file
Choose any file. It is read on your device.
See what is actually inside a file
This tool opens any file — an image, a document, an archive, or something you cannot identify — and shows its raw bytes as a hex dump: an offset column, the bytes in hexadecimal, and their ASCII representation alongside. The file is read on your device, which matters when it is something you would rather not send anywhere, including a file you are not sure is safe to open with its own application.
It is read-only. There is no editing, saving or converting here — the point is to look, not to change anything. Large files stay responsive because only the rows currently on screen are ever drawn, so scrolling through a file with millions of rows does not mean millions of elements on the page.
Why your file stays on your device
Privacy here is structural, not a promise. There is no upload step because there is no server to send the file to:
- The file is read entirely in your browser.
- The page is served as static files and makes no request that carries your data.
- The source is open and anyone can read it (MIT).
- It works offline, which is only possible because nothing leaves the device.
If you want to check for yourself, open your browser's Network panel while you open a file — no request carries its contents. Read the source.
How to use it
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Open a file
Click to choose any file, or drop it anywhere on the page. It is read locally, whatever its type.
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Read the dump
Each row shows an offset, its bytes in hex, and their ASCII representation. Switch how many bytes are shown per row — 8, 16 or 32 — to suit the file.
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Jump or search
Jump straight to a byte offset, or search for a hex byte sequence or a piece of text. The decoded-text panel can also show the bytes currently on screen in ASCII, UTF-8 or Latin-1.
FAQ
Is my file uploaded anywhere?
No. The file is read entirely in your browser. There is no server component, so its contents have no path off your device. The source is open and you can confirm this in your browser's Network panel.
What file types can it open?
Any file. There is no allow-list — the point of a hex viewer is to look inside files whose type you may not know or trust. If the file is very large (some hundreds of megabytes), a note lets you know that loading and searching may take a moment and use more memory.
Can it tell me what kind of file this is?
It checks the first bytes against a short list of common signatures — PNG, JPEG, PDF, ZIP and GZIP — and shows a guess when one matches. This is a quick sanity check, not a full file-identification tool: not matching one of those five does not mean the file is invalid, only that this quick check did not recognize it.
Can I edit the file?
No. This is a read-only viewer for inspecting bytes; it does not modify, save or export anything.
How does the search work?
Switch between hex and text search. Hex mode looks for a byte sequence you type as hex pairs (e.g. 89 50 4e 47); text mode encodes what you type as UTF-8 and searches for that byte sequence, which also covers plain ASCII. Find next/previous wraps around the file once it reaches the end.
What is the decoded-text panel for?
The ASCII column next to the hex bytes shows one character per byte, so it cannot render multi-byte text correctly. The decoded-text panel decodes the bytes currently on screen as a contiguous run, using the encoding you choose (ASCII, UTF-8 or Latin-1) — so multi-byte characters, such as an accented letter or a CJK character, show up correctly when that part of the file is actually text in that encoding.
Does it work offline?
Yes. It is a PWA. After the first visit it is cached, so it opens without a network connection. You can also install it to your home screen.
Is there a file size limit?
There is no hard limit, but the file is read fully into memory once you open it, so the practical ceiling is your device's memory. Above a few hundred megabytes a note lets you know that things may take longer and use more memory.