Convert UTF-8 to UTF-32

Fixed-width Unicode encoding: every codepoint is exactly one 32-bit unit (4 bytes). Sometimes called UCS-4. The trade-off vs UTF-8/UTF-16 is space (4 bytes per ASCII char vs 1-2) for simplicity (O(1) random access, no surrogate pairs).

UTF-16 uses 2 or 4 bytes (surrogate pair for non-BMP); UTF-32 always uses 4 bytes. So 🌍 (U+1F30D) is ONE UTF-32 unit (0001F30D) but TWO UTF-16 units (D83C DF0D surrogate pair). The grid shows each character as a single UTF-32 entry regardless of complexity.

U+0000 to U+10FFFF – 1,114,112 possible codepoints. UTF-32 has spare bits (it can technically hold up to 2^32), but Unicode caps at U+10FFFF because that’s UTF-16’s surrogate-pair limit. Values above are rejected.

U+0000FEFF prepended. Serializes as 00 00 FE FF in BE or FF FE 00 00 in LE – distinct from UTF-16 BOMs (2 bytes) so a reader can tell UTF-32 streams from UTF-16. The decoder auto-strips on detect.

U+D800-U+DFFF are reserved for UTF-16 encoding only. They don’t represent characters; encountering one in a UTF-32 stream means corruption. This tool throws explicit position-specific errors rather than silently substituting U+FFFD.

Pure space inefficiency. ASCII text is 4× the size in UTF-32 vs UTF-8. For storage, UTF-8 dominates (compact for Latin, ASCII-backward-compatible). UTF-32 is mainly used as an internal representation in some text-processing libraries and older Python “wide” builds (pre-3.3) where O(1) codepoint indexing matters.

ASCII: UTF-32 is 4× UTF-8. Latin/Cyrillic: 2×. CJK: 33% larger (4 bytes vs 3). Emoji: equal (4 bytes in both).

No. The conversion runs entirely in your browser – nothing is sent to a server, logged, or stored, and the tool keeps working offline once the page has loaded.

200,000 characters per run, roughly a short novel chapter. The cap keeps the browser responsive; for bigger jobs, split the text and run it in parts.

Inverse direction. That tool parses UTF-32 code points and produces text + UTF-8 bytes; this tool starts from UTF-8 text and produces UTF-32 code points. Both validate U+10FFFF + surrogate strictly.