URL Encoder & Decoder Online — Free
Runs 100% in your browser — your files never leave your device.
Query values, redirect targets, and path fragments break when spaces or reserved characters are inserted raw. Paste a URL component, choose encode or decode, and get the standards-based encodeURIComponent result without sending the value to a server.
How it works
- 1
Choose encode or decode
- 2
Paste the URL component
- 3
Copy the transformed output
About this tool
What percent-encoding solves
URLs can only carry a limited alphabet safely: letters, digits, and a few reserved characters. Spaces, ampersands, slashes, and non-ASCII text break URL structure when inserted raw — percent-encoding replaces each with %XX escapes so the value survives transport intact.
encodeURIComponent versus encodeURI
This tool applies encodeURIComponent semantics: it escapes everything that could break a URL component, including &, =, and ?. Use it for query values and path fragments. The looser encodeURI is for whole URLs you want to keep working — never for the pieces inside them.
The classic debugging case
A redirect breaks with "URL parameter lost" — almost always an unencoded & or ? inside a value that a router then splits. Encode the value, pass it through, and decode it on the other side. The URL parser shows exactly how a router will see the result.
Frequently asked questions
When do I encode versus decode?
Encode when you place dynamic data inside a URL; decode when you read a value out of one. A round trip of encode → transport → decode returns the original text byte for byte.
Why do spaces become %20 and plus signs appear elsewhere?
Percent-encoding turns spaces into %20 by standard. The + convention for spaces belongs to form encoding (application/x-www-form-urlencoded), a different context that trips everyone at least once.
Does encoding hide parameters from servers?
No — encoding is transport syntax, not security. Servers decode values before your application sees them. Secrets in URLs are visible in logs regardless of encoding.