Hex Viewer & Binary Viewer, Hex Editor (Large Files)

Free, no sign-in, works offline. See and edit the bytes of any file in VS Code, from a 0-byte file to a 4 GB disk image, with go to offset, search, a data inspector and copy as hex, C array, Python bytes or base64.

A PNG file open in Hex Viewer inside VS Code. Bytes 0x10 to 0x13 of the IHDR chunk are selected, and the data inspector on the right reads them as big-endian uint32 1400, the image width. The toolbar has Go to offset, Find with Hex, Text and UTF-16 modes, bytes per row, the text encoding and Copy as. The status line shows the offset, the selection, PNG image, 134.5 KB and Overwrite.

Real output from VS Code 1.142 on macOS. The file is robot-arm.png. scripts/e2e-vscode.mjs installed the packaged extension in a clean VS Code profile, opened the file and saved the window through the debug port.

Big files open at once. Only the rows on screen are read, in 64 KB pieces. In the release check a 4 GB file opened in 0.6 s, Ctrl+End went to its last byte, and the extension host used 127 MB.
You can get anywhere. Go to an offset in hex or decimal, or jump by +0x100 or -16. Find hex bytes with ?? wildcards, text, or UTF-16 text. The status bar shows the offset of the cursor.
Editing stays put. Type two hex digits to overwrite a byte; the cursor moves one byte and stops. Each byte is one undo step. Save writes only the changed bytes.

Quick start

Install Hex Viewer.
Right-click any file in the Explorer and pick "Open in Hex Viewer". Files that end in .bin, .dat, .img, .rom, .dmp or .dump open in Hex Viewer when you click them.

For a file that is already open, use "Open in Hex Viewer" in the editor title menu (...) or the tab's right-click menu, or "Reopen Editor With...". Text files such as .txt, .ts and Intel .hex files still open in the text editor. "Hex Viewer: Get Started" in the Command Palette opens a short tour.

Large files

A 4 GB sparse file at its last row, offset 0x100000030, with LASTBYTE in the text column. The row above shows NEAR-THE-4GB-EDGE at offset 0xFFFFFFF0.

Local files of any size open. The extension never reads the whole file: it reads the rows you look at, and Find reads the file in 1 MB pieces.
The scroll bar is drawn by the viewer, so it reaches the last row of a 4 GB or larger file. Drag it, use the mouse wheel, Page Up and Page Down, or Ctrl+Home and Ctrl+End.
If the file changes on disk while it is open, the view shows the new bytes. If it got shorter, a message gives the old and new size and the view moves to the new end. Nothing crashes and nothing goes blank.
Empty files and files you have no permission to read show a plain message instead of a blank tab.
Files on remote and virtual file systems open up to 256 MB (setting hexViewer.maxRemoteMB).

Find, go to and copy

firmware.bin with the 6 bytes DE AD BE EF 13 37 found at offset 0x2FFFD, across a 64 KB edge. The match is highlighted in the hex and text columns and the toolbar says Match at 0x2FFFD.

Action	Keys	Notes
Go to offset	Ctrl+G (Cmd+G)	`0x1F40`, `1F40h`, `8000`, `+0x100`, `-16`, `end`, `end-15`. Also the box at the left of the toolbar, and a click on the status bar.
Find	Ctrl+F (Cmd+F)	Hex `50 4B 03 04` with `??` for any byte, text (with Aa to ignore case) or UTF-16. Unsaved edits are found too.
Next, previous match	Enter, Shift+Enter, F3, Shift+F3	The search goes on from the start after the end. Esc stops a long search.
Copy	Ctrl+C (Cmd+C)	Hex with spaces from the hex column (setting `hexViewer.copyFormat`), text from the text column
Copy as...	toolbar	Hex, hex with spaces, C array, Python bytes, base64, UTF-8 text, Latin-1 text. Up to 32 MB.
Select	Shift + arrows, Page Up, Page Down, Home, End; drag; Ctrl+A
Switch column	Tab	Between the hex and the text column

Data inspector

The panel on the right reads the bytes at the cursor, or at the start of the selection, as:

the offset in hex and decimal, binary and octal
uint8, int8, uint16, int16, uint24, uint32, int32, uint64, int64
float16, float32, float64
ULEB128 and SLEB128, with their length
Unix time (32 and 64-bit) and Windows FILETIME
a GUID, and a UTF-8 and UTF-16 character with its code point

Click "Little-endian" to switch to big-endian. In the release check, the values at 5 offsets were the same as Python's struct and uuid modules.

Edit bytes

edit-me.bin after typing AB CD 12 at offset 0x10. The three edited bytes are colored and the tab shows unsaved changes.

Type hex digits in the hex column, or characters in the text column, to overwrite bytes. Edited bytes are colored until you save.
Paste hex (4A 5B 00, 0x4A, 0x5B or \x4a\x5b) with Ctrl+V to overwrite from the cursor.
Ctrl+Z undoes one byte, Ctrl+Shift+Z redoes, and Ctrl+S saves. Save writes only the changed bytes into the file, so it is fast on a 4 GB file. Save As writes a full copy.
Overwrite only: bytes are not inserted or deleted, so the file size does not change.
Read-only files open as view only. Set hexViewer.readOnly to turn editing off for every file.

Display

The same PNG in the light theme at 16 bytes per row, with the cursor on offset 0x10.

8, 16, 24, 32, 48 or 64 bytes per row.
Text column in ASCII, Latin-1, UTF-8, UTF-16 LE, UTF-16 BE or EBCDIC (code page 037). Control bytes show as a dot or as symbols such as ␀ and ␊.
The file type from its first bytes in the status line: PNG, JPEG, ZIP, PDF, SQLite, ELF, Mach-O, PE, Java class, WAV, WebAssembly and more.
The editor font, the theme colors in dark and light themes, and the editor font size (or hexViewer.fontSize).
Screen readers hear the offset and value of the byte under the cursor.

Settings

Setting	Default	What it does
`hexViewer.bytesPerRow`	16	Bytes in each row when a file opens
`hexViewer.encoding`	ascii	Text column encoding when a file opens
`hexViewer.controlChars`	dot	Show control bytes as a dot or as symbols
`hexViewer.uppercase`	true	4A or 4a
`hexViewer.fontSize`	0	Font size of the byte grid; 0 uses the editor font size
`hexViewer.copyFormat`	hexSpaced	What Ctrl+C copies from the hex column
`hexViewer.littleEndian`	true	Byte order of the data inspector
`hexViewer.showInspector`	true	Show the data inspector when a file opens
`hexViewer.readOnly`	false	Turn off byte editing
`hexViewer.maxRemoteMB`	256	Largest file from a remote or virtual file system
`hexViewer.askForRating`	true	Ask one time for a Marketplace rating after a few days of use. Nothing is sent anywhere.
`hexViewer.showSupportLinks`	true	Show the small Sponsor and More free viewers links in the status line

Privacy and safety

The extension makes no network calls and has no telemetry. It writes to a file only when you save. The webview runs under a strict Content Security Policy (default-src 'none', scripts by nonce, no remote sources) and gets bytes only from the extension host.

Limits

Overwrite only. Insert and delete come in a later version.
No structure templates yet (PNG chunks, ZIP entries, ELF and PE headers).
Copy as... works up to 32 MB, and a paste up to 16 MB.

Support Zovo

Zovo extensions are free, with no ads and no tracking. They are made by theluckystrike on GitHub. If this one saves you time, you can support the work:

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License

MIT