URL Encoder / Decoder

What is URL encoding?

URL encoding, also called percent-encoding, replaces characters that are not allowed in a URL with a percent sign followed by two hexadecimal digits. For example, a space becomes %20, an ampersand becomes %26, and a forward slash becomes %2F. This ensures that URLs are transmitted correctly across the internet without ambiguity. Every browser performs URL encoding behind the scenes when you submit a form or click a link that contains special characters.

When do you need to encode or decode URLs?

You need URL encoding whenever you pass user-generated text as a query parameter, build API requests by hand, or construct redirect URLs. Without encoding, characters like &, =, and # are interpreted as URL delimiters rather than literal values, which breaks your request. Decoding is the reverse: when you receive a percent-encoded string from a server log, analytics tool, or URL bar, decoding converts it back to readable text so you can inspect or modify it.

How does this tool work?

This tool uses the built-in JavaScript functions encodeURIComponent and decodeURIComponent. The encode function converts every character that is not a letter, digit, or one of - _ . ! ~ * ' ( ) into its percent-encoded form. The decode function reverses the process, turning percent-encoded sequences back into their original characters. Everything runs entirely in your browser - no data is sent to any server, and no sign-up is required.

Common use cases

Web developers encode query parameters before appending them to API URLs. QA testers decode URLs from server logs to understand what was actually requested. Marketers decode tracking links to read UTM parameters in plain text. System administrators inspect encoded paths in access logs. Anyone building or debugging URLs by hand benefits from a quick encode/decode tool that handles the conversion instantly.