HTML URL Encode
URL Encoding
URLs can only be sent over the Internet using the ASCII character-set. If a URL contains characters outside the ASCII set, the URL has to be converted.
URL encoding converts non-ASCII characters into a format that can be transmitted over the Internet.
URL encoding replaces non-ASCII characters with a "%" followed by hexadecimal digits.
URLs cannot contain spaces. URL encoding normally replaces a space with a plus (+) sign, or %20.
Reserved Characters
Certain characters are "reserved" because they may (or may not) be defined as delimiters by the generic syntax in a particular URL scheme. For example, forward slash / characters are used to separate different parts of a URL.
If data for a URL component contains character that would conflict with a reserved set of characters, which is defined as a delimiter in the URL scheme then the conflicting character must be percent-encoded before the URL is formed. Reserved characters in a URL are:
! |
# |
$ |
& |
' |
( |
) |
* |
+ |
, |
/ |
: |
; |
= |
? |
@ |
[ |
] |
%21 |
%23 |
%24 |
%26 |
%27 |
%28 |
%29 |
%2A |
%2B |
%2C |
%2F |
%3A |
%3B |
%3D |
%3F |
%40 |
%5B |
%5D |
Unreserved Characters
Characters that are allowed in a URL but do not have a reserved purpose are called unreserved. These include uppercase and lowercase letters, decimal digits, hyphen, period, underscore, and tilde. The following table lists all the unreserved characters in a URL:
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
K |
L |
M |
N |
O |
P |
Q |
R |
S |
T |
U |
V |
W |
X |
Y |
Z |
a |
b |
c |
d |
e |
f |
g |
h |
i |
j |
k |
l |
m |
n |
o |
p |
q |
r |
s |
t |
u |
v |
w |
x |
y |
z |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
- |
_ |
. |
~ |
|
