URL Encode / Decode

Percent-encode text for URLs and query strings, or decode encoded URLs back to readable text. Handles UTF-8 and the component vs full-URL distinction.

How to use this tool

Encode: paste text and choose Component (for a value you’ll put into a query string) or Full URL (for a complete address that just needs spaces and special characters escaped).

Decode: paste an encoded URL or value to see it readable. + is treated as a space, as in form data.

The rules

A URL may only contain ASCII letters, digits and a small set of symbols. Everything else must be percent-encoded as the UTF-8 bytes of the character:

Character	Encoded
space	`%20` (or `+` in form data)
`&`	`%26`
`=`	`%3D`
`?`	`%3F`
`/`	`%2F`
`#`	`%23`
`é`	`%C3%A9`
`€`	`%E2%82%AC`
`日`	`%E6%97%A5`

Characters that never need encoding: A–Z a–z 0–9 - _ . ~.

Why it matters

Special characters in a URL have jobs: ? starts the query string, & separates parameters, = separates a name from its value, # starts a fragment. If a value contains one of those characters unencoded, the URL is misread. The classic example: a search for fish & chips sent as ?q=fish & chips turns into a parameter q=fish plus a nameless parameter chips. Encoded as ?q=fish%20%26%20chips, it works.

In code

Language	Component encode	Decode
JavaScript	`encodeURIComponent(s)`	`decodeURIComponent(s)`
Python	`urllib.parse.quote(s, safe='')`	`urllib.parse.unquote(s)`
PHP	`rawurlencode($s)`	`rawurldecode($s)`
Java	`URLEncoder.encode(s, "UTF-8")` (uses `+`)	`URLDecoder.decode(s, "UTF-8")`
Go	`url.QueryEscape(s)`	`url.QueryUnescape(s)`

Common mistakes

Double encoding — %20 becomes %2520. Encode once, at the point where you build the URL.
Encoding the whole URL — turns https:// into https%3A%2F%2F. Use full-URL mode or encode only values.
Wrong charset — old systems encoded with Latin-1, producing %E9 for é instead of %C3%A9. Modern standards mandate UTF-8.
Trusting decoded input — decoded values may contain anything; validate before using them in HTML or SQL.

Frequently asked questions

What is URL encoding?

Replacing characters that aren't allowed in a URL with a % followed by their byte value in hex — a space becomes %20, an ampersand %26, é becomes %C3%A9. It's also called percent-encoding.

What's the difference between "component" and "full URL" encoding?

Component encoding escapes everything that has meaning in a URL, including / ? & = and :, so the result is safe as a single value. Full-URL encoding leaves those structural characters alone and only escapes spaces and non-ASCII, so a complete address stays valid.

Why does a space sometimes become + instead of %20?

Historical form encoding (application/x-www-form-urlencoded) uses + for spaces in query strings. %20 is the general standard. The decoder here accepts both.

Should I encode the whole URL?

Usually not. Encode each query-string value with component encoding and assemble the URL yourself; encoding an entire URL that's already correct will double-encode the % signs.

Last updated August 26, 2026.