Tool overview
What is a URL Encoder/Decoder?
URL encoding (percent-encoding) escapes reserved characters so query values and path segments stay valid in a URI.
Why use this URL Encoder?
Apply encodeURIComponent / decodeURIComponent locally when building query strings, debugging broken links, or cleaning pasted URLs.
Key Features
Encode and decode modes, instant results, one-click copy, and client-side-only processing.
How to Use
Follow these steps to get accurate results from the tool interface above.
- Select Encode to percent-encode reserved characters, or Decode to reverse an encoded query string.
- Paste plain text or an encoded URI component into the input panel—transform runs on debounced input.
- Accept Magic Paste detection when clipboard content looks percent-encoded to auto-switch to Decode mode.
- Use Swap to move output to input and flip direction for round-trip verification.
- Copy the result or pipe output to Hash Generator or JWT Decoder from the toolbar menu.
URI Encoding Type Matrix
encodeURIComponent escapes all reserved characters per RFC 3986. These inputs distinguish valid encodings from decode exceptions.
| Token Type | Valid Standard Format | Malformed Input |
|---|---|---|
| Query value | hello%20world | hello%2worldMalformed percent-escape (% not followed by two hex digits) throws URIError on decodeURIComponent. |
| Unicode scalar | %E4%B8%96%E7%95%8C | %E4%B8%G7%95%8CNon-hexadecimal escape digits cause URIError—validate hex pairs before decoding user input. |
| Reserved chars (encode) | a%2Fb%3Fc%3Dd | a/b?c=d (raw in component)Unencoded / ? & = in query values break URL parsers—encode before concatenating into URLs. |
| Plus-as-space legacy | hello+world | hello%20world vs + mismatchapplication/x-www-form-urlencoded treats + as space; decodeURIComponent does not—normalize + to %20 first if needed. |
Security Profile
Percent-encoding and decoding run synchronously in the JavaScript runtime on your machine. OAuth tokens, session IDs, and PII in query strings are never uploaded. This utility does not validate URL authority, TLS certificates, or open redirect safety—always validate decoded URLs in your application layer before navigation.
Frequently Asked Questions
Expandable answers for common debugging bottlenecks and data privacy questions.
Related tools
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Official Documentation & References
Authoritative specifications and platform documentation for this utility.