Hex to String / String to Hex

Free online hex and string converter. Space / 0x / comma separators, upper/lowercase toggle, UTF-8 aware, with clear validation of invalid hex input.

Runs locally · data never uploaded

How to use

What it does

Hexadecimal (hex) represents each byte as two hex digits. It is handy for inspecting binary data, verifying files and debugging protocols. This tool parses text as UTF-8, so non-ASCII characters like Chinese are first turned into their UTF-8 bytes before being shown as hex.

Options:

Separator: none, space, 0x prefix (e.g. 0x4f 0x60), or comma.
Uppercase: toggle between 4f and 4F.
Direction: string → hex, or hex → string.

Decoding (hex → string) automatically strips spaces, commas and 0x prefixes and validates the input: the length must be even and only 0-9 a-f A-F are allowed. Invalid input produces a clear, readable error.

Example

Convert Hello to hex (no separator, lowercase):

48656c6c6f

Convert 你好 to hex (UTF-8, space-separated):

e4 bd a0 e5 a5 bd

Common uses

Comparing two files byte for byte
Inspecting the real bytes of a character when debugging encoding/mojibake
Building or parsing binary protocols and hash inputs

FAQ

Q1.Why does Chinese turn into so many hex digits?

Chinese characters usually take 3 bytes in UTF-8, and each byte is two hex digits, so one character becomes 6 hex digits (e.g. "你" → e4 bd a0). This is standard and reversible.

Q2.What does "length must be even" mean?

Every two hex characters represent one byte, so the total number of characters must be even. If one is missing (e.g. `48656c6c6`), the input is truncated or has a stray character — check the end.

Q3.Can hex include 0x or spaces?

Yes. Decoding ignores `0x` prefixes, spaces and commas, keeping only valid hex characters, so `0x48 0x65` and `4865` are equivalent.

Q4.Is my data uploaded?

No. All conversion happens locally in your browser and works offline after a refresh.

How to use

What it does

Example

Common uses

FAQ

Related tools