Text to Hex: String and ASCII to Hexadecimal

How to convert text to hex

1. Type or paste the text into Input · Text. The hex appears in Output · Hex as you type.
2. Under the input, Charset decides how characters become bytes. Leave it on UTF-8 unless the receiving system expects something else.
3. Under the output, pick Case (lowercase or UPPERCASE), Separator (none, space, :, 0x or \x) and Bytes per line (none, 16 or 32).
4. Copy output or Download the result. The Hex → Text toggle turns it back into text, as does Hex to Text.

Output styles

The separator and case options cover the usual places hex gets pasted into. For the text Hi!:

The \x form drops straight into a string literal: printf '\x48\x69\x21' in Bash prints Hi!. Bytes per line breaks long output into rows of 16 or 32 bytes so you can count offsets by eye.

One character, one or more bytes

ASCII characters are one byte each, and UTF-8 keeps them identical, so for English text both charsets give the same hex. Everything else depends on the charset:

Characters that a charset cannot represent are replaced with ?, and the status line says how many were replaced. If hex from another system does not match yours, check the charset on both sides first.

Finding invisible characters

Converting to hex is the quickest way to see characters that look like nothing on screen. Two strings that print identically can differ in their bytes:

If a password, API key or config value is “correct but rejected”, paste it here with Separator set to space and look for any of these. The same check helps before encoding text as Base64 with Text to Base64: Base64 keeps every invisible byte, so they survive into the encoded value.

Text to hex in code

"Hi!".encode("utf-8").hex()       # '486921'
"Hi!".encode("utf-8").hex(" ")    # '48 69 21'  (separator argument, Python 3.8+)
"é".encode("latin-1").hex()       # 'e9'

const hex = Array.from(new TextEncoder().encode("café"),
  b => b.toString(16).padStart(2, "0")).join(" ");
// '63 61 66 c3 a9'

TextEncoder always produces UTF-8. The JavaScript and Python pages show the matching Base64 calls.

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