Hex Viewer

How to use

1. 1Drop a file (up to 5 MiB), pick one from disk, paste a hex string, or click a sample to load bytes.
2. 2Scroll the hex dump or use Prev page, Next page, and Jump to offset to navigate large files. Each page covers 4 KiB.
3. 3Pick a search mode (Hex or ASCII) and type a needle. Use Prev and Next to jump between matches; the active match is highlighted in amber.
4. 4Click any byte to see its hex, decimal, binary, and ASCII values, then type 1 or 2 hex digits in the Replace byte field and press Enter to overwrite it.
5. 5Use Copy hex dump, Copy hex bytes only, or Copy ASCII column only to grab the visible page, then Download to save the edited file with the original extension.

About this tool

Hex Viewer is a file-first hex dump and lightweight editor that runs entirely in your browser. Drop a file (or paste a hex string) and the bytes are laid out in the classic xxd-style format: an 8-digit zero-padded offset, sixteen 2-digit hex bytes per row with a wider gap after byte 8, and an ASCII gutter where non-printable bytes are shown as dots. The viewer paginates input into 4 KiB pages so even large files stay responsive: only the active page is rendered to the DOM. Click any byte to see its hex, decimal, binary, and ASCII values, then type one or two hex digits to replace it. Edited bytes are highlighted in green and listed in an edit-diff panel that shows every change as offset, original byte, and current byte; you can revert any single edit or all of them with one click. Search works in two modes: hex (paste 89 50 4E 47 or 89504E47 to find a PNG signature) and ASCII (type PNG or HTTP/1.1 to find the literal string). Matches are highlighted across the file, with a counter and prev/next buttons that jump the page to the active hit. A Jump to offset field accepts hex (0x10), decimal (16), or bare hex (10). Copy buttons cover the visible hex dump, the visible hex bytes, the visible ASCII gutter, and the edit diff so you can paste straight into a bug report or a code review. Download writes the current bytes (with edits applied) to a Blob with the inferred MIME type and triggers a save with an .edited suffix when changes are present. Built-in samples (PNG header, ZIP header, JPEG SOI, plain ASCII, UTF-8 mix) let you try the dump before loading your own file. Useful for inspecting magic numbers, debugging proprietary binary formats, comparing two captures byte by byte, patching a single byte in a config blob, and any other time you need to see exactly what is in a file. Files are read into the tab's memory and never leave your device.

Free to use. Works in your browser. No signup, no login.