Hex to Text Converter

About hex-to-text conversion

Hexadecimal (hex) is the base-16 number system. It uses sixteen symbols, 0 through 9 then A through F, where A to F stand for the values 10 to 15. Hex is the standard shorthand for raw bytes because one byte (8 bits, values 0 to 255) maps to exactly two hex digits. This tool reverses that shorthand: paste a sequence of hex byte pairs and it decodes them back into readable text using UTF-8.

The reason hex is so common is that it is far more compact than binary and far more byte-aligned than decimal. The byte 255 is 11111111 in binary, 255 in decimal, but a tidy FF in hex. Programmers see hex everywhere: memory addresses, HTTP byte ranges, cryptographic hashes, MAC addresses, and CSS color codes like #FF6600. Each pair of hex digits is one byte, and each byte maps to a character through an encoding.

Decoding is deterministic. Strip anything that is not a hex digit, read the digits two at a time, convert each pair to a number from 0 to 255, and look the number up in UTF-8. Because the mapping is exact and case-insensitive, the same hex always yields the same text, and valid UTF-8 hex round-trips losslessly back to its original string.

How it works: the formula

The tool cleans the input to bare hex digits, reads them in pairs, and decodes the resulting byte array as UTF-8 with the browser's TextDecoder:

clean = input.replace(/[^0-9a-fA-F]/g, '')   // keep only hex digits
// length must be even (2 digits per byte)
bytes = [];
for (i = 0; i < clean.length; i += 2)
    bytes.push(parseInt(clean.substr(i, 2), 16))   // pair -> a number
text  = new TextDecoder().decode(new Uint8Array(bytes))   // bytes -> UTF-8

parseInt(pair, 16) reads each two-character chunk in base 16; TextDecoder reassembles single- and multi-byte UTF-8 sequences into characters. It runs entirely on your device: open developer tools, watch the Network tab, and no requests fire while you decode.

Worked example: decoding "48 65 6c 6c 6f"

1. Clean and pair. Removing spaces gives the pairs 48, 65, 6c, 6c, 6f (five bytes).
2. Convert the first pair. 48 in base 16 = 4 x 16 + 8 = 72, which is the letter H.
3. Convert the rest. 65 = 101 (e), 6c = 108 (l), 6c = 108 (l), 6f = 111 (o).
4. Result: the text is Hello (5 bytes decoded).

A multi-byte example: the pairs c3 a9 are decimals 195 and 169, which UTF-8 decodes as a single accented character, "e-acute". Two hex bytes, one visible letter.

Hex reference: bytes to characters

Common pitfalls

• Odd digit count. Hex must have an even number of characters because each byte is two digits. A missing or extra digit triggers an error; check for a dropped character.
• Including the 0x prefix or # sign. Markers like 0x or a leading # are not hex digits. They are stripped, but mixing them mid-stream can shift byte alignment, so remove them first.
• Confusing a hex color with hex bytes. A CSS color like FF6600 is three bytes that decode to control characters, not a readable word. Hex-to-text is for byte sequences that represent text.
• Assuming one byte equals one character. That holds only for ASCII. Multi-byte UTF-8 sequences (accents, emoji) need all their hex pairs present and in order.
• Worrying about letter case. Hex is case-insensitive: 4F and 4f are the same byte. No need to normalise before pasting.

Related tools

Frequently asked questions