View the first bytes of any file as a hex dump with its detected signature.
Try an example
Load a ready-made sample into this tool and run it. Every result you see is calculated live by the tool itself — nothing here is a pre-written answer.
Sample: File: sample.txt
How to Use
- Choose any file (up to 10 MB).
- Click Run Hex.
- Read the first 256 bytes as hex and ASCII.
What this hex file viewer does
This hex file viewer shows the first 256 bytes of any file as a hex dump, with each byte written in hexadecimal next to its printable character. The opening bytes of a file carry its signature — the short sequence that identifies a PNG, PDF, ZIP and many other formats — so a quick look here can reveal what a file really is.
When to use it
Open a file here when an extension looks doubtful, a program refuses to open a download, or you are learning how file formats begin. Files of up to 10 MB are accepted, although only the opening bytes are displayed. The detected signature is shown alongside the dump to help you name the format.
Good to know
Only the first 256 bytes are ever shown; the rest of the file is never displayed, and nothing can be edited here. This is a viewer, not a hex editor. Your file is processed locally in your browser and is never sent to this site's server.
Frequently asked questions
Can I edit bytes with this tool?
No. The viewer is read-only and displays the first 256 bytes as hex and text. It cannot change, repair or save a modified file. For editing you would need a dedicated hex editor on your own computer.
Why only the first 256 bytes?
Because the beginning of a file is where the identifying signature and header information live. For checking a file's real format, the first bytes answer the question; displaying millions of bytes would add nothing but a very long page.
What does the ASCII column show?
It shows each byte as a character where one exists. Letters and digits appear as themselves, while bytes with no printable character appear as a placeholder. Header text inside formats such as PDF often shows up readably in this column.
How to use Hex File Viewer
- Choose any file (up to 10 MB).
- Click Run Hex.
- Read the first 256 bytes as hex and ASCII.
Limitations
Only the first 256 bytes are shown; the full file is never displayed. Files are processed in your browser and never sent to the site's server.