Original: Questions about URL escape characters (URL encoding)
Yesterday, I was going to go online to find out what new book has come out recently. After asking a friend, he gave me a strange address: %31%32%36%2E%61%6D/hEeGv4, which seems to be different from the URL. Copy the string on the side to the browser address bar and open it. As a result, the Taobao page can be opened normally. So what is the matter with this string of addresses that does not look like a URL?
Through searching, I know that when sending a URL on the Internet, the characters in the URL can only be ASCII characters, but there are few ASCII characters, and the URL often contains characters other than the ASCII character set, such as non-English characters, Chinese characters, special symbols, etc. etc., so the URL needs to be converted. This process is called URL encoding, or URL escaping, and essentially converts a URL that contains non-ASCII characters into a valid ASCII character format.
When URL encoding, each non-ASCII character is replaced with "%hh" format, where hh is a two-digit hexadecimal number, which corresponds to the encoded value of the character in the ISO-8859-1 character set. For example, if the two Chinese characters "China" appear in the URL, they should be converted to "%D6%D0%B9%FA". Since one Chinese character requires two bytes, "China" is replaced by four ASCII characters. .
Knowing what the URL escape character is all about, you can understand the above address. We reverse-encode "%31%32%36%2E%61%6D/hEeGv4" to get "126.am/hEeGv4", we can find that this is a URL that omits "http://", and the super The long Taobao link has shortened the URL, and copied it into the browser address bar, the browser will recognize the address and automatically add "http://", so we can open it normally.
I used this webpage to decode URLs: http://www.nengcha.com/code/urlDecode.asp.
Attached is a comparison table of ASCII characters and URL encoding.
ASCII characters URL-encoded
spaces %20
! %21
” %22
# %23
$ %24
% %25
& %26
' %27
( %28
) %29
* %2A
+ %2B
, %2C
– %2D
. %2E
/ %2F
0 %30
1 %31
2 %32
3 %33
4 %34
5 %35
6 %36
7 %37
8 %38
9 %39
: %3A
; %3B
< %3C = %3D > %3E
? %3F
@ %40
A %41
B %42
C %43
D %44
E %45
F %46
G %47
H %48
I %49
J %4A
K %4B
L %4C
M %4D
N %4E
O %4F
P %50
Q %51
R %52
S %53
T %54
U %55
V %56
W %57
X %58
Y %59
Z %5A
[ %5B
\ %5C
] %5D
^ %5E
_ %5F
` %60
a %61
b %62
c %63
d %64
e %65
f %66
g %67
h %68
i %69
j %6A
k %6B
l %6C
m %6D
n %6E
o %6F
p %70
q %71
r %72
s %73
t %74
u %75
v %76
w %77
x %78
y %79
z %7A
{ %7B
| %7C
} %7D
~ %7E
%7F
€ 80
% 81
, %82
ƒ 83
% „ 84%
… % 8
† %86
‡ 87
% ˆ %88
‰ %8
Š %8A
› %8B
Π%8C
%8D
Ž %8E
%8F
%90
'%91
' %92
“%93
”94%
• % 96 –
96
% — 97%
˜ %98
%™ 99
% š %9A
› %9B
œ %9C
%9D
ž %9E
Ÿ %9F
%A0
¡ %A1
¢ %A2
£ %A3
%A4
¥ %A5
| %A6
§ %A7
¨ %A8
© %A9
ª %AA
« %AB
¬ %AC
¯ %AD
® %AE
¯ %AF
° %B0
± %B1
² %B2
³ %B3
´ %B4
µ %B5
¶ %B6
%B7
¸ %B8
¹ %B9
º %BA
» %BB
¼ %BC
½ %BD
¾ ¾ %BE
¿ %BF
À %C0
Á %C1
 %C2
à %C3
Ä% C4
Å% C5
Æ% C6
Ç% C7
È% C8
É% C9
Ê% CA
Ë% CB
Ì% CC
Í% CD
Î% CE
Ï% CF
Ð% D0
Ñ% D1
Ò% D2
Ó% D3
Ô% D4
Õ% D5
Ö% D6
% D7
Ø% D8
Ù% D9
Ú% DA
Û% DB
Ü% DC
Ý% DD
Þ% DE
ß% DF
à% E0
á% E1
â% E2
ã% E3
ä% E4
å% E5
æ% E6
ç% E7
è% E8
é% E9
ê% EA
ë% EB
ì% EC
í% ED
î% EE
ï% EF
ð% F0
ñ% F1
ò% F2
ó% F3
ô% F4
õ% F5
ö% F6
÷% F7
ø% F8
ù% F9
ú% FA
û% FB
ü% FC
ý% FD
þ% FE
ÿ% FF