How do I URL encode a string in Python?

Use urllib.parse.quote with safe="" for a single path segment, quote_plus for a query value, or urlencode to build a whole query string from a dictionary.

Should I encode a slash inside a path segment?

Yes, as %2F, if the slash is part of the value rather than a path separator. Be aware that some servers and proxies decode %2F before routing, so values that may contain slashes are often safer in the query string.

Developer Utilities

URL Encoding Characters: What to Encode and Where

The same character can be fine in one part of a URL and break another. Here is a reference table of what each JavaScript and Python function does with the characters that matter.

Updated October 18, 20262 min readTool runs in your browser

URL encoding characters correctly depends on where in the URL they go: a / is fine in a path, an & is fine in a fragment, and both break a query value. The URL Encoder encodes text in the browser, and its page explains why encodeURI and encodeURIComponent do different jobs. This guide is a reference: what each function does with each character, and which one to use for each part.

URL encoding characters: a reference table

Output of each JavaScript function, run in Node:

Char   encodeURIComponent   encodeURI   URLSearchParams
space  %20                  %20         +
+      %2B                  +           %2B
/      %2F                  /           %2F
?      %3F                  ?           %3F
#      %23                  #           %23
&      %26                  &           %26
=      %3D                  =           %3D
%      %25                  %25         %25
@      %40                  @           %40
:      %3A                  :           %3A
é      %C3%A9               %C3%A9      %C3%A9
~      ~                    ~           %7E
'      '                    '           %27
(      (                    (           %28

Non-ASCII characters are always encoded as their UTF-8 bytes, so é becomes two escapes. Note the rows where the functions disagree: encodeURI leaves +, /, ?, #, & and = alone because they have meaning in a full URL, and URLSearchParams writes a space as + and also escapes ~, ' and (.

Which function for which part of a URL

A path segment, such as a product name in /products/{name}: encodeURIComponent. It encodes /, so a name containing a slash cannot add a path level.
A query parameter value: URLSearchParams, or encodeURIComponent if you build the string yourself. Both encode &, = and #, which would otherwise end the value early.
A whole URL that is already assembled: encodeURI, which only fixes characters that can never appear raw, such as spaces and non-ASCII letters. Never run it on a URL that contains user data in its query.
A fragment: encodeURIComponent is the safe default.

const url = new URL("https://shop.example.com/search");
url.searchParams.set("q", "socks & shoes");
url.searchParams.set("next", "/cart?step=2");
url.toString();
// "https://shop.example.com/search?q=socks+%26+shoes&next=%2Fcart%3Fstep%3D2"

Building URLs through the URL object is the least error-prone option: you set raw values and it encodes them for the right part.

URL encoding in Python

from urllib.parse import quote, quote_plus, urlencode

quote("a/b c")              # 'a/b%20c'     keeps / by default
quote("a/b c", safe="")     # 'a%2Fb%20c'   for a path segment
quote_plus("socks & shoes") # 'socks+%26+shoes'
urlencode({"q": "SAVE 10", "next": "/cart?a=1"})
# 'q=SAVE+10&next=%2Fcart%3Fa%3D1'

quote leaves / unencoded unless you pass safe="", a common source of broken path segments. quote_plus and urlencode use + for spaces, matching what HTML forms send, while quote uses %20.

URL Decoder

Decode percent-encoded URL strings back to plain, readable text.

Base64 Encode

Encode text or files to Base64, with an optional URL-safe variant.

Online JSON Formatter & Validator

Pretty-print JSON with configurable indentation and instant validation.

How to Decode a URL Parameter That Contains Another URL

Tracking links and login redirects nest one URL inside another, encoded once per layer. Here is how to unwrap them correctly in JavaScript and Python, and the redirect check that keeps it safe.

What Is Base64 Used For? Data URIs, Auth, JWT, Email

Base64 turns bytes into plain text so they can travel where only text is allowed. Here are the five places developers meet it most, with real examples, and the cases where it is the wrong tool.

How to Format JSON Files Automatically with Prettier

Two formatters can disagree about the same JSON file. Here is how a team picks one, applies it in every editor and before every commit, and makes CI enforce it.

Frequently asked questions

Browse all guides