How to use it
- Choose a file, or switch to Paste text and type or paste the text.
- Scroll with the mouse wheel, the scroll bar, or the arrow and page keys, and click a byte to select it.
- Type a position such as 0x1000 in Go to offset, or type bytes such as DE AD BE EF under Search and press Find next.
- Read the Byte inspector for the bytes under the cursor, as integers, floats and the UTF-8 character.
Reading the dump
Each row shows 16 bytes. The offset at the start of the row is the position of its first byte, counted from 0 in hexadecimal. The ASCII column shows the bytes that are printable ASCII letters, digits and punctuation, and a dot for every other byte, such as a control character or a byte of a non-ASCII letter.
The page reads only the rows on the screen, a few kilobytes at a time, so a large file opens quickly and is never loaded whole. Nothing is uploaded: the file is read in your browser.
Search and offsets
A search for hex bytes looks for exactly those bytes, with or without spaces and 0x. A search for text looks for the text as UTF-8 bytes (RFC 3629), so a letter such as ğ is the two bytes C4 9F. Each search starts after the cursor and wraps to the start of the data. An offset can be decimal, such as 4096, or hexadecimal with a 0x prefix, such as 0x1000.
The byte inspector
The inspector reads the bytes from the cursor onward as each type would. Little-endian reads the first byte as the least significant one, and big-endian reads it as the most significant. For example, the bytes 01 02 03 04 are 67305985 as a little-endian 32-bit integer and 16909060 as a big-endian one. Floats are read in the IEEE 754 format, so a value such as 0.1 is shown as the nearest binary fraction.
Worked example: the word Hello
The text Hello is five bytes. In the dump it starts at offset 00000000, and its first row reads 48 65 6C 6C 6F in hexadecimal and Hello in ASCII. The table shows that row.
Each letter of Hello is one byte, so the same row is the same whatever the byte order.
| Offset | Bytes in hexadecimal | ASCII |
|---|---|---|
| 00000000 | 48 65 6C 6C 6F | Hello |
Frequently asked questions
Why does the ASCII column show dots?
A dot stands for a byte that is not a printable ASCII character, such as a control code, a zero or a byte of a non-ASCII letter. The hexadecimal column shows its real value.
What is the difference between little-endian and big-endian?
The two orders put the same bytes in reverse. The bytes 01 02 03 04 are 0x04030201 little-endian and 0x01020304 big-endian, so read a number in the order its format uses.
Why does my text search not find the word?
A text search looks for UTF-8 bytes. A file saved in another encoding, such as Windows-1254, stores the same letters as other bytes, so search for those bytes in hexadecimal instead.
Can I change the bytes here?
No. The viewer only reads the file, so the original is never changed, and the page writes nothing to your device.
How large a file can I open?
Up to 2 GB. The page reads the rows on the screen and each search in pieces, so a search through a large file can take a while, and the result appears when it is found.
Is my file sent anywhere?
No. The file is read in your browser, and nothing is uploaded to our server or stored there.
Sources
- RFC 3629: UTF-8, a transformation format of ISO 10646
- IEEE 754, floating-point arithmetic (Wikipedia)
- Endianness (Wikipedia)
Figures and text last checked on Tuesday, November 10, 2026.