UTF-8 byte meaning lookup table

UTF-8 byte meanings

	-0	-1	-2	-3	-4	-5	-6	-7	-8	-9	-A	-B	-C	-D	-E	-F
0-	NUL	SOH	STX	ETX	EOT	ENQ	ACK	BEL	BS	TAB	LF	VT	FF	CR	SO	SI
1-	DLE	DC1	DC2	DC3	DC4	NAK	SYN	ETB	CAN	EM	SUB	ESC	FS	GS	RS	US
2-		!	"	#	$	%	&	'	(	)	*	+	,	-	.	/
3-	0	1	2	3	4	5	6	7	8	9	:	;	<	=	>	?
4-	@	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O
5-	P	Q	R	S	T	U	V	W	X	Y	Z	[	\	]	^	_
6-	`	a	b	c	d	e	f	g	h	i	j	k	l	m	n	o
7-	p	q	r	s	t	u	v	w	x	y	z	{	\|	}	~	DEL
8-	+00	+01	+02	+03	+04	+05	+06	+07	+08	+09	+0A	+0B	+0C	+0D	+0E	+0F
9-	+10	+11	+12	+13	+14	+15	+16	+17	+18	+19	+1A	+1B	+1C	+1D	+1E	+1F
A-	+20	+21	+22	+23	+24	+25	+26	+27	+28	+29	+2A	+2B	+2C	+2D	+2E	+2F
B-	+30	+31	+32	+33	+34	+35	+36	+37	+38	+39	+3A	+3B	+3C	+3D	+3E	+3F
C-	0000	0040	0080	00C0	0100	0140	0180	01C0	0200	0240	0280	02C0	0300	0340	0380	03C0
D-	0400	0440	0480	04C0	0500	0540	0580	05C0	0600	0640	0680	06C0	0700	0740	0780	07C0
E-	0000	1000	2000	3000	4000	5000	6000	7000	8000	9000	A000	B000	C000	D000	E000	F000
F-	0000	40000	80000	C0000	100000	4	4	4	5	5	5	5	6	6	X	X
	-0	-1	-2	-3	-4	-5	-6	-7	-8	-9	-A	-B	-C	-D	-E	-F

80–BF: continuation bytes.
C0–DF: two-byte sequences, followed by a continuation byte. U+0080 to U+07FF.
E0–EF: three-byte sequences, followed by two continuation bytes. U+0800 to U+FFFF.
F0–F8: four-byte sequences, followed by three continuation bytes. U+FFFF to U+10FFFF.
C0, C1: overlong encodings of U+00 to U+7F, hence forbidden.
E0, F0: some continuation bytes start overlong (hence forbidden) sequences.
ED: can start forbidden sequences that encode UTF-16 surrogate pairs in the U+D800 to U+DFFF range. (These are allowed in variants like CESU-8 and WTF-8.)
F4: can start forbidden sequences that decode to a code point greater than U+10FFFF.
F5–FD: 4- to 6-byte encodings of code points greater than U+10FFFF.
FE, FF: no meaning; U+FEFF is the byte order mark used in UTF-16, encoded in UTF-8 as EF-BB-BF.
See also "UTF-8 decoding code".

In three-byte sequences the continuation bytes' values are shifted left by six bits, or multiplied by 64:

	-0	-1	-2	-3	-4	-5	-6	-7	-8	-9	-A	-B	-C	-D	-E	-F
8-	+000	+040	+080	+0C0	+100	+140	+180	+1C0	+200	+240	+280	+2C0	+300	+340	+380	+3C0
9-	+400	+440	+480	+4C0	+500	+540	+580	+5C0	+600	+640	+680	+6C0	+700	+740	+780	+7C0
A-	+800	+840	+880	+8C0	+900	+940	+980	+9C0	+A00	+A40	+A80	+AC0	+B00	+B40	+B80	+BC0
B-	+C00	+C40	+C80	+CC0	+D00	+D40	+D80	+DC0	+E00	+E40	+E80	+EC0	+F00	+F40	+F80	+FC0

And in four-byte sequences they're shifted again:

	-0	-1	-2	-3	-4	-5	-6	-7	-8	-9	-A	-B	-C	-D	-E	-F
8-	+00···	+01···	+02···	+03···	+04···	+05···	+06···	+07···	+08···	+09···	+0A···	+0B···	+0C···	+0D···	+0E···	+0F···
9-	+10···	+11···	+12···	+13···	+14···	+15···	+16···	+17···	+18···	+19···	+1A···	+1B···	+1C···	+1D···	+1E···	+1F···
10-	+20···	+21···	+22···	+23···	+24···	+25···	+26···	+27···	+28···	+29···	+2A···	+2B···	+2C···	+2D···	+2E···	+2F···
11-	+30···	+31···	+32···	+33···	+34···	+35···	+36···	+37···	+38···	+39···	+3A···	+3B···	+3C···	+3D···	+3E···	+3F···

Created 2022-09-14. Index.