HTML URL Encoding

URL encoding is the practice of translating unprintable characters or characters with special meaning within URLs to a representation that is unambiguous and universally accepted by web browsers and servers. These characters include:

  • ASCII control characters – Unprintable characters typically used for output control. Character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal). A complete encoding table is given below.
  • Non-ASCII control characters – These are characters beyond the ASCII character set of 128 characters. This range is part of the ISO-Latin character set and ncludes the entire “top half” of the ISO-Latin set 80-FF hex (128-255 decimal). A complete encoding table is given below.
  • Reserved characters – These are special characters such as the dollar sign, ampersand, plus, common, forward slash, colon, semi-colon, equals sign, question mark, and “at” symbol. All of these can have different meanings inside a URL so need to be encoded. A complete encoding table is given below.
  • Unsafe characters – These are space, quotation marks, less than symbol, greater than symbol, pound character, percent character, Left Curly Brace, Right Curly Brace , Pipe, Backslash, Caret, Tilde, Left Square Bracket , Right Square Bracket, Grave Accent. These character present the possibility of being misunderstood within URLs for various reasons. These characters should also always be encoded. A complete encoding table is given below.

The encoding notation replaces the desired character with three characters: a percent sign and two hexadecimal digits whose correspond to the position of the character in the ASCII character set.

Example:

One of the most common special characters is the space. You can’t type a space in a URL directly. A space position in the character set is 20 hexadecimal. So you can use %20 in place a space when passing your request to the server.

http://www.example.com/new%20pricing.html

This URL actually retrieves a document named new pricing.html from the www.example.com

ASCII control characters encoding

This includes the encoding for character ranges 00-1F hex (0-31 decimal) and 7F (127 decimal)

Decimal Hex Value Character URL Encode
0 00 %00
1 01 %01
2 02 %02
3 03 %03
4 04 %04
5 05 %05
6 06 %06
7 07 %07
8 08 backspace %08
9 09 tab %09
10 0a linefeed %0a
11 0b %0b
12 0c %0c
13 0d carriage return %0d
14 0e %0e
15 0f %0f
16 10 %10
17 11 %11
18 12 %12
19 13 %13
20 14 %14
21 15 %15
22 16 %16
23 17 %17
24 18 %18
25 19 %19
26 1a %1a
27 1b %1b
28 1c %1c
29 1d %1d
30 1e %1e
31 1f %1f
127 7f %7f

Non-ASCII control characters encoding

This includes the encoding for the entire “top half” of the ISO-Latin set 80-FF hex (128-255 decimal.)

Decimal Hex Value Character URL Encode
128 80 € %80
129 81  %81
130 82 ‚ %82
131 83 Æ’ %83
132 84 „ %84
133 85 … %85
134 86 † %86
135 87 ‡ %87
136 88 ˆ %88
137 89 ‰ %89
138 8a Å  %8a
139 8b ‹ %8b
140 8c Å’ %8c
141 8d  %8d
142 8e Ž %8e
143 8f  %8f
144 90  %90
145 91 ‘ %91
146 92 ’ %92
147 93 “ %93
148 94 ” %94
149 95 • %95
150 96 – %96
151 97 — %97
152 98 ˜ %98
153 99 â„¢ %99
154 9a Å¡ %9a
155 9b › %9b
156 9c Å“ %9c
157 9d  %9d
158 9e ž %9e
159 9f Ÿ %9f
160 a0 %a0
161 a1 ¡ %a1
162 a2 ¢ %a2
163 a3 £ %a3
164 a4 ¤ %a4
165 a5 ¥ %a5
166 a6 ¦ %a6
167 a7 § %a7
168 a8 ¨ %a8
169 a9 © %a9
170 aa ª %aa
171 ab « %ab
172 ac ¬ %ac
173 ad %ad
174 ae ® %ae
175 af ¯ %af
176 b0 ° %b0
177 b1 ± %b1
178 b2 ² %b2
179 b3 ³ %b3
180 b4 ´ %b4
181 b5 µ %b5
182 b6 ¶ %b6
183 b7 · %b7
184 b8 ¸ %b8
185 b9 ¹ %b9
186 ba º %ba
187 bb » %bb
188 bc ¼ %bc
189 bd ½ %bd
190 be ¾ %be
191 bf ¿ %bf
192 c0 À %c0
193 c1 Á %c1
194 c2 Â %c2
195 c3 Ã %c3
196 c4 Ä %c4
197 c5 Ã… %c5
198 c6 Æ %v6
199 c7 Ç %c7
200 c8 È %c8
201 c9 É %c9
202 ca Ê %ca
203 cb Ë %cb
204 cc Ì %cc
205 cd Í %cd
206 ce ÃŽ %ce
207 cf Ï %cf
208 d0 Ð %d0
209 d1 Ñ %d1
210 d2 Ã’ %d2
211 d3 Ó %d3
212 d4 Ô %d4
213 d5 Õ %d5
214 d6 Ö %d6
215 d7 × %d7
216 d8 Ø %d8
217 d9 Ù %d9
218 da Ú %da
219 db Û %db
220 dc Ü %dc
221 dd Ý %dd
222 de Þ %de
223 df ß %df
224 e0 à %e0
225 e1 á %e1
226 e2 â %e2
227 e3 ã %e3
228 e4 ä %e4
229 e5 å %e5
230 e6 æ %e6
231 e7 ç %e7
232 e8 è %e8
233 e9 é %e9
234 ea ê %ea
235 eb ë %eb
236 ec ì %ec
237 ed í %ed
238 ee î %ee
239 ef ï %ef
240 f0 ð %f0
241 f1 ñ %f1
242 f2 ò %f2
243 f3 ó %f3
244 f4 ô %f4
245 f5 õ %f5
246 f6 ö %f6
247 f7 ÷ %f7
248 f8 ø %f8
249 f9 ù %f9
250 fa ú %fa
251 fb û %fb
252 fc ü %fc
253 fd ý %fd
254 fe þ %fe
255 ff ÿ %ff

Reserved characters encoding

Following is the table to be used to encode reserved characters.

Decimal Hex Value Char URL Encode
36 24 $ %24
38 26 & %26
43 2b + %2b
44 2c , %2c
47 2f / %2f
58 3a : %3a
59 3b ; %3b
61 3d = %3d
63 3f ? %3f
64 40 @ %40

Unsafe characters encoding

Following is the table to be used to encode unsafe characters.

Decimal Hex Value Char URL Encode
32 20 space %20
34 22 %22
60 3c < %3c
62 3e > %3e
35 23 # %23
37 25 % %25
123 7b { %7b
125 7d } %7d
124 7c | %7c
92 5c \ %5c
94 5e ^ %5e
126 7e ~ %7e
91 5b [ %5b
93 5d ] %5d
96 60 ` %60

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