Encode a search query
Raw
hello world & more
Encoded
hello%20world%20%26%20more
Spaces become %20, and the & becomes %26 so it isn't mistaken for a query-parameter separator.
URL Encoder / Decoder
Safely encode and decode URL components.
Last updated
DecodedPaste text to begin
Encoded
Percent-encoded or decoded output appears here — Unicode-aware.
What is a URL encoder?
A URL encoder (also called percent-encoder or URI encoder) replaces characters that are reserved or unsafe in URLs with % followed by two hex digits. Developers reach for it when building query strings, escaping path segments, sharing URLs that contain spaces or non-ASCII characters, and debugging redirects.
URLs are restricted to a small set of ASCII characters. Anything outside that set — spaces, accents, emoji, or reserved symbols like ?, #, &, = when used in data — must be percent-encoded so it survives the trip from the browser to the server.
JavaScript exposes two encoding functions: encodeURI (preserves URL structure: /, ?, #, &) and encodeURIComponent (encodes everything reserved). Use encodeURIComponent for *values* you stuff into query strings, and encodeURI for *whole URLs* you want to keep functional.
What you'll learn while encoding URLs
- Percent-encoding replaces a single byte with
%plus two hex digits — for example, a space becomes%20. - Reserved characters (
:/?#&=+) have meaning in URL structure. They must be encoded when used as data, not as separators. - Non-ASCII text (accents, emoji, Cyrillic, CJK) is first turned into UTF-8 bytes, then each byte is percent-encoded.
How to encode and decode URLs step by step
Pick a direction
Choose Encode if you have raw text and want it URL-safe. Choose Decode if you have a
%-encoded string and want the original text back.Choose the encoding mode
Pick
encodeURIComponent(encodes everything reserved) for query string values; pickencodeURI(keeps structure) for whole URLs.Paste your input
Paste the raw text or the encoded URL. Multiline input works for batch decoding.
Copy the result
Copy the encoded or decoded value. The conversion runs locally in your browser, so secrets in URLs stay on your machine.
Common URL encodings quick reference
Characters you'll see encoded most often, with their percent-encoded form. Reserved character semantics come from RFC 3986.
| Character | Encoded | Why |
|---|---|---|
| space | %20 | Spaces aren't allowed in URLs |
! | %21 | Reserved by some servers |
# | %23 | Marks the start of a fragment |
$ | %24 | Reserved character |
& | %26 | Separates query parameters |
+ | %2B | Means space in form-encoded bodies |
/ | %2F | Path separator |
: | %3A | Separates scheme and host |
= | %3D | Separates key from value in query string |
? | %3F | Marks the start of the query string |
@ | %40 | Separates userinfo and host |
| UTF-8 byte | %C3%A9 | Each non-ASCII byte is encoded |
URL encoding examples to try
Encode non-ASCII characters
Raw
café
Encoded
caf%C3%A9
é is the UTF-8 byte sequence 0xC3 0xA9, so the encoded form has *two* %XX groups for that single character.
encodeURI vs encodeURIComponent
Raw
https://example.com/path?q=hello world
encodeURI
https://example.com/path?q=hello%20world
encodeURIComponent
https%3A%2F%2Fexample.com%2Fpath%3Fq%3Dhello%20world
encodeURI keeps URL structure intact (slashes, ?, =). encodeURIComponent encodes everything reserved — use it on values you put inside a query string, never on a whole URL.
Common URL encoding mistakes
- Using
encodeURIfor query string values — the&and=survive the encoding and break parameter parsing. - Encoding a URL twice.
%2520instead of%20is the classic sign of double-encoding bugs. - Forgetting that
+means space inapplication/x-www-form-urlencodedbodies but is a literal+in a URL path or query.
URL Encoding FAQ
What is URL encoding?
URL encoding (also called percent-encoding) is a way to represent characters that have special meaning in URLs, or that aren't safe to transmit, by replacing them with
% followed by two hex digits.What is the difference between encodeURI and encodeURIComponent?
encodeURI preserves URL structure characters (/, ?, #, &, =, +). encodeURIComponent encodes them all, which is what you want for individual *values* placed inside a URL — query parameter values, path segments, fragments. See the MDN references for encodeURI and encodeURIComponent.Why does a space become %20?
Spaces aren't allowed in URLs, so they're replaced with
%20, the percent-encoding of the ASCII space character (0x20 in hex).When should I URL-encode?
Encode any user-supplied or dynamic value before putting it into a URL — query string values, path segments, redirect targets, OAuth parameters. Never trust raw input to be URL-safe.
Can URL encoding be reversed?
Yes — that's URL decoding.
decodeURI, decodeURIComponent, or any URL-decoder reverses the percent-encoding back to the original characters.