bin2hex

Bin2hex is a data-encoding function that converts binary data into a hexadecimal string representation. It is not an encryption or compression tool; rather, it encodes each byte of input as two hexadecimal characters, producing a text-safe form suitable for transmission or display in text-based environments.

The operation is straightforward: for every byte in the input, two hex digits are produced, resulting in an output length that is exactly twice the input length. The encoding is per-byte and does not interpret the input as a multi-byte integer, making the function endian-agnostic and reliable for arbitrary binary data.

Commonly associated with PHP, bin2hex takes a binary string as input and returns a lowercase hexadecimal string. For example, bin2hex("Hi") yields "4869" because H is 0x48 and i is 0x69. The function is often paired with hex2bin, which reverses the process and converts a hex string back to binary data. Similar concepts exist in other languages, such as hexadecimal encoding utilities in Python or JavaScript, though naming conventions may vary.

Typical use cases include preparing binary data for safe transport in text formats (such as JSON or URLs), debugging by displaying contents in a readable form, or creating simple checksums. It is not intended for security or compression, and developers should be mindful of memory usage when processing very large data streams.