Output will appear here...encodeURIComponent (component)
Escapes everything with special meaning in a URL. Use for individual values - query parameters, path segments, cookie values - never for a whole URL (it would encode :// too).
EncodesReserved delimiters : / ? # [ ] @ $ & + , ; =, spaces, and all non-ASCII characters
PreservesRFC 3986 unreserved characters: A-Z a-z 0-9 - _ . ~ plus ! * ' ( )
a=1&b=2 → a%3D1%26b%3D2 (safe to embed as a single query value)
Category:encoding
Mode:Offline
Version:1.0.0
Access:Free
What is URL Encoder/Decoder?
URL Encoder/Decoder converts text to and from percent-encoding (also called URL encoding), the escape scheme defined by RFC 3986 that makes arbitrary strings safe to put inside a URL. Characters like &, =, ?, # and / have structural meaning in URLs - if a query-string value contains a literal "&", the server will split your parameter in half unless that character is escaped as %26. This tool gives you all three encoding variants developers actually encounter: encodeURIComponent for individual values, encodeURI for complete URLs, and application/x-www-form-urlencoded (spaces as +) for HTML form bodies.
The distinction between modes matters more than most tutorials admit. encodeURIComponent escapes every reserved delimiter, so it is the right choice for a single query parameter, a path segment, or a redirect target embedded in another URL - but running it on a full URL would mangle https:// into https%3A%2F%2F. encodeURI preserves the delimiters (: / ? # & =) so an entire URL stays navigable while spaces and non-ASCII characters like é or 日本 still get escaped to their UTF-8 percent-encoded form. The form-urlencoded mode matches what browsers send when you submit a <form>: identical to encodeURIComponent except spaces become "+" instead of "%20" - a legacy quirk that still trips up API integrations today.
Everything runs 100% client-side in your browser using the same native encodeURIComponent/decodeURI machinery your production JavaScript uses, so results match exactly what your code will produce. Nothing you paste - OAuth callback URLs, signed S3 links, tokens, session IDs - ever leaves your machine. The decoder also catches malformed input (a stray % not followed by two hex digits throws URIError in JavaScript) and reports a clear error instead of failing silently.
How to use URL Encoder/Decoder?
1
Paste your text or URL
Drop the raw value into the input area - a query parameter value, a full URL with spaces and unicode, or an encoded string like a%3D1%26b%3D2 you pulled from server logs and want to decode.
2
Pick the encoding mode
Choose encodeURIComponent for individual values (query params, path segments), encodeURI for complete URLs where :// and ? must survive, or form-urlencoded when you are building an HTML form body or debugging a POST payload with + signs.
3
Encode or decode
Click Encode to percent-encode the input, or Decode to reverse it. Decoding handles %XX sequences and, in form mode, converts + back to spaces. Malformed sequences produce a readable error instead of a blank output.
4
Copy or swap
Copy the result to your clipboard with one click, or use the swap button to move the output back into the input - handy when a value has been double-encoded (%2520) and needs a second decode pass.
Key Features
Three real-world modes
encodeURIComponent, encodeURI, and application/x-www-form-urlencoded - the three variants you actually meet in query strings, full URLs, and form bodies
RFC 3986 compliant
Uses the browser-native encoding functions, so unreserved characters (A-Z a-z 0-9 - _ . ~) pass through untouched and UTF-8 multi-byte sequences encode correctly
Safe decoding with clear errors
Malformed percent sequences like a stray "%" report exactly what went wrong instead of throwing an unhandled URIError
Swap input and output
One click moves the result back into the input - perfect for unwrapping double-encoded values layer by layer
Frequently Asked Questions
Use encodeURIComponent for a single value that goes inside a URL - a query parameter, path segment, or cookie value - because it escapes delimiters like &, =, / and ?. Use encodeURI only when you have a complete URL and want to escape invalid characters (spaces, unicode) without destroying its structure. Rule of thumb: if the string contains :// that should stay intact, use encodeURI; otherwise use encodeURIComponent.
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