Hex Encoder and Decoder

What is hexadecimal encoding?

Hex writes each byte as exactly two characters drawn from the digits 0 to 9 and the letters A to F. A 10-byte input becomes 20 hexadecimal characters. This tool encodes to lowercase and accepts either case when decoding.

Choose Encode for typed text or an uploaded file, or Decode to recover the original bytes from valid hexadecimal. Several inputs per run are fine, and results arrive as files.

Why hex, when it doubles the size

Because you can read it. The mapping is positional and fixed: byte three of the file is always characters five and six of the output. Nothing shifts, nothing is grouped across boundaries, and you can point at a spot in the middle of a hex dump and know exactly which byte you are looking at.

That property is why hex is the standard way to show hashes, checksums, memory dumps, file signatures, colour values, and anything else a person needs to compare by eye. Base64 is denser and completely opaque to that kind of inspection.

Are there alternatives?

Base64 costs about a third in overhead against hex's 100 percent, and is the better pick when nobody reads the output. Base32 sits between the two and survives case-mangling. Ascii85 is denser than all of them.

For eyeballing the first bytes of an unknown file, hex remains the most direct option.

Fun facts and more info

Hex gets confused with hashing because hashes are nearly always shown in hex. The hash does the fingerprinting. The hex only makes the result printable, and on its own it protects nothing.

Because two characters map to exactly one byte, valid hex always has an even length. An odd number of characters means something was truncated.