File Hex Viewer

View any file as a hex dump with ASCII sidebar, byte highlighting, and offset navigation.

Tested tool guide Tested browser tools Checked August 16, 2026

What File Hex Viewer does, with a checked example

File Hex Viewer lays out a selected file byte by byte: hexadecimal values in the main grid, corresponding printable ASCII characters alongside them, and offsets that identify each byte's position. Highlighting lets you correlate a byte in the hex area with its ASCII representation, while offset navigation jumps to a location without scanning every row. The common surprise is that the ASCII sidebar is only a convenience view. It does not identify the file's text encoding, and bytes outside printable ASCII may appear as placeholders even when they belong to valid UTF-8 text or binary data.

Worked example

A concrete input and expected output from the current implementation.

Input

A file containing exactly three bytes: 0x41 0x42 0x43

Expected output

Starting offset: 0; hex bytes: 41 42 43; ASCII sidebar: ABC

The first byte has offset zero. In ASCII, hexadecimal 41, 42, and 43 represent A, B, and C respectively.

How the result is produced

Hex rows and offsets

Each displayed hexadecimal pair represents one byte, from 00 through FF. The offset marks the zero-based byte position at the start of a row; moving right increases the position by one. Offset navigation therefore targets a byte location, not a line number, character count, or address stored inside the file. The final row can contain fewer bytes than earlier rows.

Hex and ASCII pairing

Selecting or highlighting a byte links its hex cell to the matching position in the ASCII sidebar, making short signatures and embedded labels easier to spot. Printable ASCII bytes are shown as characters; other byte values need a neutral placeholder because they have no printable ASCII glyph. The original byte value remains the hex pair, so use the hex grid for exact inspection.

Good uses

Verifying that a file begins with an expected magic number or header before trusting its filename extension.
Inspecting a parser error at a reported byte offset and viewing the raw bytes surrounding that location.
Finding embedded ASCII labels, version strings, or delimiters inside an otherwise binary file.

Limits and checks

The ASCII sidebar is not a UTF-8, UTF-16, or legacy-encoding decoder; one valid character may span several displayed bytes.
A familiar header suggests a format but does not establish that the entire file is valid, complete, or safe.
Byte offsets are positions in raw data; they can differ from character indexes, editor columns, and numeric values stored inside the file.

Common questions

Can the viewer determine a file's type from its first bytes?

It can expose a recognizable signature at the beginning of a file, but a matching prefix alone does not validate the rest of the structure. Some formats lack unique signatures, and different formats can share introductory bytes. Use the displayed header as evidence to compare with the format's specification. When no definitive signature exists, the viewer cannot identify the type conclusively.

Are the displayed offsets the same as character positions?

No. Offsets refer to bytes, starting with zero, rather than decoded characters. For single-byte ASCII they often appear to match character indexes. They diverge when text uses multibyte encodings, when a byte order mark is present, or when binary fields precede the text. Jump using the byte position reported by a byte-oriented parser or format specification.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.