UTF-32 LE vs UTF-16 LE

UTF-32 LE

Unicode

Fixed-width encoding using 4 bytes per character. Simple to process but memory-inefficient. Little-endian byte order.

IANA Name: UTF-32LE
Byte Width: 4–4 bytes
BOM: FF FE 00 00
Introduced: 2003

UTF-16 LE

Unicode

Little-endian UTF-16. Used internally by Windows, Java, and .NET. Variable-width: 2 bytes for BMP characters, 4 bytes (surrogate pairs) for supplementary characters.

IANA Name: UTF-16LE
Byte Width: 2–4 bytes
BOM: FF FE
Introduced: 1996

Both UTF-32 LE and UTF-16 LE are Unicode encodings — they represent the same 138,571 characters. The difference is in how the bytes are arranged. The table below shows how the first 128 codepoints (the ASCII range) are encoded in each.

ASCII Range (U+0000–U+007F)

Char	Codepoint	UTF-32 LE	UTF-16 LE	Same?
	U+0000	00 00 00 00	00 00	≠
	U+0001	01 00 00 00	01 00	≠
	U+0002	02 00 00 00	02 00	≠
	U+0003	03 00 00 00	03 00	≠
	U+0004	04 00 00 00	04 00	≠
	U+0005	05 00 00 00	05 00	≠
	U+0006	06 00 00 00	06 00	≠
	U+0007	07 00 00 00	07 00	≠
	U+0008	08 00 00 00	08 00	≠
	U+0009	09 00 00 00	09 00	≠
	U+000A	0A 00 00 00	0A 00	≠
	U+000B	0B 00 00 00	0B 00	≠
	U+000C	0C 00 00 00	0C 00	≠
	U+000D	0D 00 00 00	0D 00	≠
	U+000E	0E 00 00 00	0E 00	≠
	U+000F	0F 00 00 00	0F 00	≠
	U+0010	10 00 00 00	10 00	≠
	U+0011	11 00 00 00	11 00	≠
	U+0012	12 00 00 00	12 00	≠
	U+0013	13 00 00 00	13 00	≠
	U+0014	14 00 00 00	14 00	≠
	U+0015	15 00 00 00	15 00	≠
	U+0016	16 00 00 00	16 00	≠
	U+0017	17 00 00 00	17 00	≠
	U+0018	18 00 00 00	18 00	≠
	U+0019	19 00 00 00	19 00	≠
	U+001A	1A 00 00 00	1A 00	≠
	U+001B	1B 00 00 00	1B 00	≠
	U+001C	1C 00 00 00	1C 00	≠
	U+001D	1D 00 00 00	1D 00	≠
	U+001E	1E 00 00 00	1E 00	≠
	U+001F	1F 00 00 00	1F 00	≠
	U+0020	20 00 00 00	20 00	≠
!	U+0021	21 00 00 00	21 00	≠
"	U+0022	22 00 00 00	22 00	≠
#	U+0023	23 00 00 00	23 00	≠
$	U+0024	24 00 00 00	24 00	≠
%	U+0025	25 00 00 00	25 00	≠
&	U+0026	26 00 00 00	26 00	≠
'	U+0027	27 00 00 00	27 00	≠
(	U+0028	28 00 00 00	28 00	≠
)	U+0029	29 00 00 00	29 00	≠
*	U+002A	2A 00 00 00	2A 00	≠
+	U+002B	2B 00 00 00	2B 00	≠
,	U+002C	2C 00 00 00	2C 00	≠
-	U+002D	2D 00 00 00	2D 00	≠
.	U+002E	2E 00 00 00	2E 00	≠
/	U+002F	2F 00 00 00	2F 00	≠
0	U+0030	30 00 00 00	30 00	≠
1	U+0031	31 00 00 00	31 00	≠
2	U+0032	32 00 00 00	32 00	≠
3	U+0033	33 00 00 00	33 00	≠
4	U+0034	34 00 00 00	34 00	≠
5	U+0035	35 00 00 00	35 00	≠
6	U+0036	36 00 00 00	36 00	≠
7	U+0037	37 00 00 00	37 00	≠
8	U+0038	38 00 00 00	38 00	≠
9	U+0039	39 00 00 00	39 00	≠
:	U+003A	3A 00 00 00	3A 00	≠
;	U+003B	3B 00 00 00	3B 00	≠
<	U+003C	3C 00 00 00	3C 00	≠
=	U+003D	3D 00 00 00	3D 00	≠
>	U+003E	3E 00 00 00	3E 00	≠
?	U+003F	3F 00 00 00	3F 00	≠
@	U+0040	40 00 00 00	40 00	≠
A	U+0041	41 00 00 00	41 00	≠
B	U+0042	42 00 00 00	42 00	≠
C	U+0043	43 00 00 00	43 00	≠
D	U+0044	44 00 00 00	44 00	≠
E	U+0045	45 00 00 00	45 00	≠
F	U+0046	46 00 00 00	46 00	≠
G	U+0047	47 00 00 00	47 00	≠
H	U+0048	48 00 00 00	48 00	≠
I	U+0049	49 00 00 00	49 00	≠
J	U+004A	4A 00 00 00	4A 00	≠
K	U+004B	4B 00 00 00	4B 00	≠
L	U+004C	4C 00 00 00	4C 00	≠
M	U+004D	4D 00 00 00	4D 00	≠
N	U+004E	4E 00 00 00	4E 00	≠
O	U+004F	4F 00 00 00	4F 00	≠
P	U+0050	50 00 00 00	50 00	≠
Q	U+0051	51 00 00 00	51 00	≠
R	U+0052	52 00 00 00	52 00	≠
S	U+0053	53 00 00 00	53 00	≠
T	U+0054	54 00 00 00	54 00	≠
U	U+0055	55 00 00 00	55 00	≠
V	U+0056	56 00 00 00	56 00	≠
W	U+0057	57 00 00 00	57 00	≠
X	U+0058	58 00 00 00	58 00	≠
Y	U+0059	59 00 00 00	59 00	≠
Z	U+005A	5A 00 00 00	5A 00	≠
[	U+005B	5B 00 00 00	5B 00	≠
\	U+005C	5C 00 00 00	5C 00	≠
]	U+005D	5D 00 00 00	5D 00	≠
^	U+005E	5E 00 00 00	5E 00	≠
_	U+005F	5F 00 00 00	5F 00	≠
`	U+0060	60 00 00 00	60 00	≠
a	U+0061	61 00 00 00	61 00	≠
b	U+0062	62 00 00 00	62 00	≠
c	U+0063	63 00 00 00	63 00	≠
d	U+0064	64 00 00 00	64 00	≠
e	U+0065	65 00 00 00	65 00	≠
f	U+0066	66 00 00 00	66 00	≠
g	U+0067	67 00 00 00	67 00	≠
h	U+0068	68 00 00 00	68 00	≠
i	U+0069	69 00 00 00	69 00	≠
j	U+006A	6A 00 00 00	6A 00	≠
k	U+006B	6B 00 00 00	6B 00	≠
l	U+006C	6C 00 00 00	6C 00	≠
m	U+006D	6D 00 00 00	6D 00	≠
n	U+006E	6E 00 00 00	6E 00	≠
o	U+006F	6F 00 00 00	6F 00	≠
p	U+0070	70 00 00 00	70 00	≠
q	U+0071	71 00 00 00	71 00	≠
r	U+0072	72 00 00 00	72 00	≠
s	U+0073	73 00 00 00	73 00	≠
t	U+0074	74 00 00 00	74 00	≠
u	U+0075	75 00 00 00	75 00	≠
v	U+0076	76 00 00 00	76 00	≠
w	U+0077	77 00 00 00	77 00	≠
x	U+0078	78 00 00 00	78 00	≠
y	U+0079	79 00 00 00	79 00	≠
z	U+007A	7A 00 00 00	7A 00	≠
{	U+007B	7B 00 00 00	7B 00	≠
\|	U+007C	7C 00 00 00	7C 00	≠
}	U+007D	7D 00 00 00	7D 00	≠
~	U+007E	7E 00 00 00	7E 00	≠
	U+007F	7F 00 00 00	7F 00	≠

Other Comparisons

UTF-32 LE Reference UTF-16 LE Reference All Encodings Swap comparison →