Paste your text — the tool encodes it to UTF-8 via TextEncoder, then formats each byte as two hex digits. ASCII characters give one byte (two hex chars); accented letters, CJK and emoji give 2–4 bytes each. Output style is configurable: lowercase or uppercase, with or without space separators, and with an optional 0x prefix per byte.
Decoder mode strips whitespace and 0x prefixes, then reads pairs of hex digits as bytes and decodes the resulting UTF-8. Malformed UTF-8 sequences produce the Unicode replacement character (U+FFFD) rather than throwing. Useful for hex dumps, embedded firmware strings, JSON \u escapes, and inspecting raw byte values in debug output.
Configurable. Lowercase (ff) is the convention in most modern languages and JSON \u escapes; uppercase (FF) is more common in older C and assembly tooling.
Both. The decoder strips whitespace and 0x prefixes before reading byte pairs, so 'ff a3 0x4c' and 'ffa34c' both decode identically.
UTF-8. Pasting an emoji like 🎉 gives F0 9F 8E 89 — four bytes — rather than the UTF-16 surrogate pair.
The trailing nibble is ignored and a warning shown. Each byte requires exactly two hex digits.
Explore the full suite of Encode tools and 290+ other free utilities at Chunky Munster.