URL Encoder & Decoder
Encode or decode URLs and query parameters. Handles Unicode, special characters, and percent-encoding. 100% client-side.
No data sent to serverRelated Tools
What is URL Encoding?
URL encoding (also called percent-encoding) is defined in RFC 3986, the URI specification. It converts characters that are not valid in URLs — or that have special meaning in URLs — into a percent sign (%) followed by two hexadecimal digits representing the byte value. For example, a space becomes %20, an ampersand becomes %26, and the Korean character "한" (UTF-8 bytes 0xED 0x95 0x9C) becomes %ED%95%9C.
Reserved vs unreserved characters
RFC 3986 splits ASCII into two groups. Unreserved characters (A-Z, a-z, 0-9, and -_.~) can appear in URLs as-is and must NOT be encoded. Reserved characters (:/?#[]@!$&'()*+,;=) have meaning in URL syntax (delimiting scheme, host, query, etc.) and must be encoded if they're meant as data rather than syntax. Everything else (control characters, non-ASCII bytes) must be encoded.
encodeURI vs encodeURIComponent
JavaScript provides two encoders. encodeURI() encodes only characters illegal anywhere in a URL — it leaves reserved characters like :/?# alone, so it's used for whole URLs. encodeURIComponent() additionally encodes reserved characters — use it for query parameter values and path segments. This tool's "Standard" button uses encodeURIComponent; "Encode All" goes further and encodes !'()*~ as well (matching RFC 3986 strict mode).
⚠️ Reference Only
Output is generated based on your input and is provided for reference. Results may vary depending on your specific use case, edge cases, or environment-specific behavior. We do not guarantee accuracy of conversions, validations, or computed values.
Always verify critical outputs against official documentation or production environments. We are not responsible for any decisions or losses based on these tool results.
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