URL encoding

Convert characters in a URL to be “percent encoded”, or reverse them.

e.g. # becomes %23.

HTML

• w3schools.com/tags/ref_urlencode.ASP - Reference table and conversion tool. Note the form tool will not convert certain characters like - or ., nor will JS EncodeURIComponent.
• url-encode-decode.com - Conversion tool
• urlencoder.org - Conversion tool

Javascript

• encodeURI
  • Encode an entire URL. Preserves the domain and characters like ? and =.
  • See Mozilla docs or W3 schools.
  • Note escaped:

      A-Z a-z 0-9 ; , / ? : @ & = + $ - _ . ! ~ * ' ( ) #
    

• encodeURIComponent
  • Encode piece of a URL.
  • See source
• decodeURI
  • Reverse an encoded URL.
• decodeURIComponent
  • Reverse an encoded piece of a URL.

Example:

> encodeURI('https://example.com?q=Hello, world!')
"https://example.com?q=Hello,%20world!"

// If you actually want a character comma to be encoded and not skipped, you would use this and then build the URL.
> encodeURIComponent('Hello, world!')
"Hello%2C%20world!"

> decodeURI("Hello,%20world!")
"Hello, world!"

> decodeURI("https://example.com?q=Hello,%20world!")
"https://example.com?q=Hello, world!"

Python

This is all for Python 3.

>> import urllib.parse
>>> urllib.parse.quote_plus('Hello, world!')
'Hello%2C+world%21'

This can be set as a Bash alias.

$ alias urlencode='python3 -c "import sys, urllib.parse; print(urllib.parse.quote_plus(sys.argv[1]));"'

$ urlencode 'Hello, world!'
Hello%2C+world%21