HTML URL Encoding Reference

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URL encoding converts characters into a format that can be transmitted over the Internet.

URL - Uniform Resource Locator

Web browsers request pages from web servers by using a URL.

The URL is the address of a web page, like: http://www.w3schools.com.

URL Encoding

URLs can only be sent over the Internet using the ASCII character-set.

Since URLs often contain characters outside the ASCII set, the URL has to be converted into a valid ASCII format.

URL encoding replaces unsafe ASCII characters with a "%" followed by two hexadecimal digits.

URLs cannot contain spaces. URL encoding normally replaces a space with a plus (+) sign or with %20.

Try It Yourself

If you click the "Submit" button below, the browser will URL encode the input before it is sent to the server. A page at the server will display the received input. In this case you will get an error page but if you look at the data in the address bar you will see how URL encode handles the input.

Try some other input and click Submit again.

URL Encoding Functions

In JavaScript, PHP, and ASP there are functions that can be used to URL encode a string.

In JavaScript you can use the encodeURI() function.

PHP has the rawurlencode() function, and ASP has the Server.URLEncode() function.

Click the "URL Encode" button to see how the JavaScript function encodes the text.

Note: The JavaScript function encodes space as %20.

ASCII Encoding Reference

Your browser will encode input, according to the character-set used in your page.

The default character-set in HTML5 is UTF-8.

Character From Windows - 1252 From UTF - 8
space %20 %20
! %21 %21
" %22 %22
# %23 %23
$ %24 %24
% %25 %25
& %26 %26
' %27 %27
( %28 %28
) %29 %29
* %2A %2A
+ %2B %2B
, %2C %2C
- %2D %2D
. %2E %2E
/ %2F %2F
0 %30 %30
1 %31 %31
2 %32 %32
3 %33 %33
4 %34 %34
5 %35 %35
6 %36 %36
7 %37 %37
8 %38 %38
9 %39 %39
: %3A %3A
; %3B %3B
< %3C %3C
= %3D %3D
> %3E %3E
? %3F %3F
@ %40 %40
A %41 %41
B %42 %42
C %43 %43
D %44 %44
E %45 %45
F %46 %46
G %47 %47
H %48 %48
I %49 %49
J %4A %4A
K %4B %4B
L %4C %4C
M %4D %4D
N %4E %4E
O %4F %4F
P %50 %50
Q %51 %51
R %52 %52
S %53 %53
T %54 %54
U %55 %55
V %56 %56
W %57 %57
X %58 %58
Y %59 %59
Z %5A %5A
[ %5B %5B
\ %5C %5C
] %5D %5D
^ %5E %5E
_ %5F %5F
` %60 %60
a %61 %61
b %62 %62
c %63 %63
d %64 %64
e %65 %65
f %66 %66
g %67 %67
h %68 %68
i %69 %69
j %6A %6A
k %6B %6B
l %6C %6C
m %6D %6D
n %6E %6E
o %6F %6F
p %70 %70
q %71 %71
r %72 %72
s %73 %73
t %74 %74
u %75 %75
v %76 %76
w %77 %77
x %78 %78
y %79 %79
z %7A %7A
{ %7B %7B
| %7C %7C
} %7D %7D
~ %7E %7E
  %7F %7F
` %80 %E2%82%AC
 %81 %81
‚ %82 %E2%80%9A
ƒ %83 %C6%92
„ %84 %E2%80%9E
… %85 %E2%80%A6
† %86 %E2%80%A0
‡ %87 %E2%80%A1
ˆ %88 %CB%86
‰ %89 %E2%80%B0
Š %8A %C5%A0
‹ %8B %E2%80%B9
Π%8C %C5%92
 %8D %C5%8D
Ž %8E %C5%BD
 %8F %8F
 %90 %C2%90
‘ %91 %E2%80%98
’ %92 %E2%80%99
“ %93 %E2%80%9C
” %94 %E2%80%9D
• %95 %E2%80%A2
– %96 %E2%80%93
— %97 %E2%80%94
˜ %98 %CB%9C
™ %99 %E2%84
š %9A %C5%A1
› %9B %E2%80
œ %9C %C5%93
 %9D %9D
ž %9E %C5%BE
Ÿ %9F %C5%B8
  %A0 %C2%A0
¡ %A1 %C2%A1
¢ %A2 %C2%A2
£ %A3 %C2%A3
¤ %A4 %C2%A4
¥ %A5 %C2%A5
¦ %A6 %C2%A6
§ %A7 %C2%A7
¨ %A8 %C2%A8
© %A9 %C2%A9
ª %AA %C2%AA
« %AB %C2%AB
¬ %AC %C2%AC
­ %AD %C2%AD
® %AE %C2%AE
¯ %AF %C2%AF
° %B0 %C2%B0
± %B1 %C2%B1
² %B2 %C2%B2
³ %B3 %C2%B3
´ %B4 %C2%B4
µ %B5 %C2%B5
%B6 %C2%B6
· %B7 %C2%B7
¸ %B8 %C2%B8
¹ %B9 %C2%B9
º %BA %C2%BA
» %BB %C2%BB
¼ %BC %C2%BC
½ %BD %C2%BD
¾ %BE %C2%BE
¿ %BF %C2%BF
À %C0 %C3%80
Á %C1 %C3%81
 %C2 %C3%82
à %C3 %C3%83
Ä %C4 %C3%84
Å %C5 %C3%85
Æ %C6 %C3%86
Ç %C7 %C3%87
È %C8 %C3%88
É %C9 %C3%89
Ê %CA %C3%8A
Ë %CB %C3%8B
Ì %CC %C3%8C
Í %CD %C3%8D
Î %CE %C3%8E
Ï %CF %C3%8F
Ð %D0 %C3%90
Ñ %D1 %C3%91
Ò %D2 %C3%92
Ó %D3 %C3%93
Ô %D4 %C3%94
Õ %D5 %C3%95
Ö %D6 %C3%96
× %D7 %C3%97
Ø %D8 %C3%98
Ù %D9 %C3%99
Ú %DA %C3%9A
Û %DB %C3%9B
Ü %DC %C3%9C
Ý %DD %C3%9D
Þ %DE %C3%9E
ß %DF %C3%9F
à %E0 %C3%A0
á %E1 %C3%A1
â %E2 %C3%A2
ã %E3 %C3%A3
ä %E4 %C3%A4
å %E5 %C3%A5
æ %E6 %C3%A6
ç %E7 %C3%A7
è %E8 %C3%A8
é %E9 %C3%A9
ê %EA %C3%AA
ë %EB %C3%AB
ì %EC %C3%AC
í %ED %C3%AD
î %EE %C3%AE
ï %EF %C3%AF
ð %F0 %C3%B0
ñ %F1 %C3%B1
ò %F2 %C3%B2
ó %F3 %C3%B3
ô %F4 %C3%B4
õ %F5 %C3%B5
ö %F6 %C3%B6
÷ %F7 %C3%B7
ø %F8 %C3%B8
ù %F9 %C3%B9
ú %FA %C3%BA
û %FB %C3%BB
ü %FC %C3%BC
ý %FD %C3%BD
þ %FE %C3%BE
ÿ %FF %C3%BF

URL Encoding Reference

The ASCII control characters %00-%1F were originally designed to control hardware devices.

Control characters have nothing to do inside a URL.

ASCII Character Description URL - encoding
Nul null character %00
SOH start of header %01
STX start of text %02
ETX end of text %03
EOT end of transmission %04
ENQ enquiry %05
ACK acknowledge %06
BEL bell (ring) %07
BS backspace %08
HT horizontal tab %09
LF line feed %0A
VT vertical tab %0B
FF form feed %0C
CR carriage return %0D
SO shift out %0E
SI shift in %0F
DLE data link escape %10
DC1 device control 1 %11
DC2 device control 2 %12
DC3 device control 3 %13
DC4 device control 4 %14
NAK negative acknowledge %15
SYN synchronize %16
ETB end transmission block %17
CAN cancel %18
EM end of medium %19
SUB substitute %1A
ESC escape %1B
FS file separator %1C
GS group separator %1D
RS record separator %1E
US unit separator %1F


 







HTML Language Code Reference

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ISO Language Codes

The HTML lang attribute can be used to declare the language of a Web page or a portion of a Web page. This is meant to assist search engines and browsers.

According to the W3C recommendation you should declare the primary language for each Web page with the lang attribute inside the <html> tag, like this:

<html lang="en">
...
</html>

In XHTML, the language is declared inside the <html> tag as follows:

<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
...
</html>

ISO 639-1 Language Codes

ISO 639-1 defines abbreviations for languages.

In HTML and XHTML they can be used in the lang and xml:lang attributes.

See also: next reference for country codes.

Language ISO Code
Abkhazian ab
Afar aa
Afrikaans af
Albanian sq
Amharic am
Arabic ar
Aragonese an
Armenian hy
Assamese as
Aymara ay
Azerbaijani az
Bashkir ba
Basque eu
Bengali (Bangla) bn
Bhutani dz
Bihari bh
Bislama bi
Breton br
Bulgarian bg
Burmese my
Byelorussian (Belarusian) be
Cambodian km
Catalan ca
Cherokee  
Chewa  
Chinese zh
Chinese (Simplified) zh-Hans
Chinese (Traditional) zh-Hant
Corsican co
Croatian hr
Czech cs
Danish da
Divehi  
Dutch nl
Edo  
English en
Esperanto eo
Estonian et
Faeroese fo
Farsi fa
Fiji fj
Finnish fi
Flemish  
French fr
Frisian fy
Fulfulde  
Galician gl
Gaelic (Scottish) gd
Gaelic (Manx) gv
Georgian ka
German de
Greek el
Greenlandic kl
Guarani gn
Gujarati gu
Haitian Creole ht
Hausa ha
Hawaiian  
Hebrew he, iw
Hindi hi
Hungarian hu
Ibibio  
Icelandic is
Ido io
Igbo  
Indonesian id, in
Interlingua ia
Interlingue ie
Inuktitut iu
Inupiak ik
Irish ga
Italian it
Japanese ja
Javanese jv
Kannada kn
Kanuri  
Kashmiri ks
Kazakh kk
Kinyarwanda (Ruanda) rw
Kirghiz ky
Kirundi (Rundi) rn
Konkani  
Korean ko
Kurdish ku
Laothian lo
Latin la
Latvian (Lettish) lv
Limburgish ( Limburger) li
Lingala ln
Lithuanian lt
Macedonian mk
Malagasy mg
Malay ms
Malayalam ml
Maltese mt
Maori mi
Marathi mr
Moldavian mo
Mongolian mn
Nauru na
Nepali ne
Norwegian no
Occitan oc
Oriya or
Oromo (Afaan Oromo) om
Papiamentu  
Pashto (Pushto) ps
Polish pl
Portuguese pt
Punjabi pa
Quechua qu
Rhaeto-Romance rm
Romanian ro
Russian ru
Sami (Lappish)  
Samoan sm
Sangro sg
Sanskrit sa
Serbian sr
Serbo-Croatian sh
Sesotho st
Setswana tn
Shona sn
Sichuan Yi ii
Sindhi sd
Sinhalese si
Siswati ss
Slovak sk
Slovenian sl
Somali so
Spanish es
Sundanese su
Swahili (Kiswahili) sw
Swedish sv
Syriac  
Tagalog tl
Tajik tg
Tamazight  
Tamil ta
Tatar tt
Telugu te
Thai th
Tibetan bo
Tigrinya ti
Tonga to
Tsonga ts
Turkish tr
Turkmen tk
Twi tw
Uighur ug
Ukrainian uk
Urdu ur
Uzbek uz
Venda  
Vietnamese vi
Volapük vo
Wallon wa
Welsh cy
Wolof wo
Xhosa xh
Yi  
Yiddish yi, ji
Yoruba yo
Zulu zu


 







HTTP Status Messages

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When a browser requests a service from a web server, an error might occur.

This is a list of HTTP status messages that might be returned:

1xx: Information

Message: Description:
100 Continue The server has received the request headers, and the client should proceed to send the request body
101 Switching Protocols The requester has asked the server to switch protocols
103 Checkpoint Used in the resumable requests proposal to resume aborted PUT or POST requests

2xx: Successful

Message: Description:
200 OK The request is OK (this is the standard response for successful HTTP requests)
201 Created The request has been fulfilled, and a new resource is created 
202 Accepted The request has been accepted for processing, but the processing has not been completed
203 Non-Authoritative Information The request has been successfully processed, but is returning information that may be from another source
204 No Content The request has been successfully processed, but is not returning any content
205 Reset Content The request has been successfully processed, but is not returning any content, and requires that the requester reset the document view
206 Partial Content The server is delivering only part of the resource due to a range header sent by the client

3xx: Redirection

Message: Description:
300 Multiple Choices A link list. The user can select a link and go to that location. Maximum five addresses  
301 Moved Permanently The requested page has moved to a new URL 
302 Found The requested page has moved temporarily to a new URL 
303 See Other The requested page can be found under a different URL
304 Not Modified Indicates the requested page has not been modified since last requested
306 Switch Proxy No longer used
307 Temporary Redirect The requested page has moved temporarily to a new URL
308 Resume Incomplete Used in the resumable requests proposal to resume aborted PUT or POST requests

4xx: Client Error

Message: Description:
400 Bad Request The request cannot be fulfilled due to bad syntax
401 Unauthorized The request was a legal request, but the server is refusing to respond to it. For use when authentication is possible but has failed or not yet been provided
402 Payment Required Reserved for future use
403 Forbidden The request was a legal request, but the server is refusing to respond to it
404 Not Found The requested page could not be found but may be available again in the future
405 Method Not Allowed A request was made of a page using a request method not supported by that page
406 Not Acceptable The server can only generate a response that is not accepted by the client
407 Proxy Authentication Required The client must first authenticate itself with the proxy
408 Request Timeout The server timed out waiting for the request
409 Conflict The request could not be completed because of a conflict in the request
410 Gone The requested page is no longer available
411 Length Required The "Content-Length" is not defined. The server will not accept the request without it 
412 Precondition Failed The precondition given in the request evaluated to false by the server
413 Request Entity Too Large The server will not accept the request, because the request entity is too large
414 Request-URI Too Long The server will not accept the request, because the URL is too long. Occurs when you convert a POST request to a GET request with a long query information 
415 Unsupported Media Type The server will not accept the request, because the media type is not supported 
416 Requested Range Not Satisfiable The client has asked for a portion of the file, but the server cannot supply that portion
417 Expectation Failed The server cannot meet the requirements of the Expect request-header field

5xx: Server Error

Message: Description:
500 Internal Server Error A generic error message, given when no more specific message is suitable
501 Not Implemented The server either does not recognize the request method, or it lacks the ability to fulfill the request
502 Bad Gateway The server was acting as a gateway or proxy and received an invalid response from the upstream server
503 Service Unavailable The server is currently unavailable (overloaded or down)
504 Gateway Timeout The server was acting as a gateway or proxy and did not receive a timely response from the upstream server
505 HTTP Version Not Supported The server does not support the HTTP protocol version used in the request
511 Network Authentication Required The client needs to authenticate to gain network access


 







HTTP Methods: GET vs. POST

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The two most used HTTP methods are: GET and POST.

What is HTTP?

The Hypertext Transfer Protocol (HTTP) is designed to enable communications between clients and servers.

HTTP works as a request-response protocol between a client and server.

A web browser may be the client, and an application on a computer that hosts a web site may be the server.

Example: A client (browser) submits an HTTP request to the server; then the server returns a response to the client. The response contains status information about the request and may also contain the requested content.

Two HTTP Request Methods: GET and POST

Two commonly used methods for a request-response between a client and server are: GET and POST.

The GET Method

Note that the query string (name/value pairs) is sent in the URL of a GET request:

/test/demo_form.asp?name1=value1&name2=value2

Some other notes on GET requests:

The POST Method

Note that the query string (name/value pairs) is sent in the HTTP message body of a POST request:

POST /test/demo_form.asp HTTP/1.1
Host: w3schools.com
name1=value1&name2=value2

Some other notes on POST requests:

Compare GET vs. POST

The following table compares the two HTTP methods: GET and POST.

  GET POST
BACK button/Reload Harmless Data will be re-submitted (the browser should alert the user that the data are about to be re-submitted)
Bookmarked Can be bookmarked Cannot be bookmarked
Cached Can be cached Not cached
Encoding type application/x-www-form-urlencoded application/x-www-form-urlencoded or multipart/form-data. Use multipart encoding for binary data
History Parameters remain in browser history Parameters are not saved in browser history
Restrictions on data length Yes, when sending data, the GET method adds the data to the URL; and the length of a URL is limited (maximum URL length is 2048 characters) No restrictions
Restrictions on data type Only ASCII characters allowed No restrictions. Binary data is also allowed
Security GET is less secure compared to POST because data sent is part of the URL

Never use GET when sending passwords or other sensitive information!		 POST is a little safer than GET because the parameters are not stored in browser history or in web server logs
Visibility Data is visible to everyone in the URL Data is not displayed in the URL

Other HTTP Request Methods

The following table lists some other HTTP request methods:

Method Description
HEAD Same as GET but returns only HTTP headers and no document body
PUT Uploads a representation of the specified URI
DELETE Deletes the specified resource
OPTIONS Returns the HTTP methods that the server supports
CONNECT Converts the request connection to a transparent TCP/IP tunnel

 







Pixels to Ems Conversion

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The tool below allows you to work out the em sizes from pixels (or vice versa) when working on scaling font sizes in CSS.

Pixel to Em Converter

Set a default pixel size:

px

Convert PX to EM:
px

Convert EM to PX:
em

Result:


Body Font Size

In the table below, select a body font size in pixels (px) to display a complete "px to em and percent" conversion table.

Tip: The default font size is usually 16px.

Note What is the difference between PX, EM and Percent?
Pixel is a static measurement, while percent and EM are relative measurements. The size of an EM or percent depends on its parent. If the text size of body is 16 pixels, then 150% or 1.5 EM will be 24 pixels (1.5 * 16). Look at CSS Units for more measurement units.

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