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Encoders

URL Encoder / Decoder

Percent-encode text for safe use in URLs, decode percent-encoded strings, or parse a full URL to inspect its components and query parameters.

How it works

URLs may only contain a specific set of ASCII characters. Any character outside that set must be percent-encoded: replaced with a % followed by its two-digit hexadecimal byte value. For example, a space becomes %20.

This tool uses encodeURIComponent and decodeURIComponent for component encoding, and the browser's URL API for full URL parsing. For encoding characters to be safely embedded in HTML markup rather than URLs, use the HTML Entity Encoder / Decoder instead.

Common uses

  • Query string values — encode user input before appending to a URL: ?q=hello+world
  • Redirect URLs — encode the destination URL when passing it as a query parameter
  • API debugging — decode a URL from a log or curl command to see the original parameters
  • OAuth callbacks — decode the redirect_uri and state parameters from OAuth flows

🔒 Privacy

All URL encoding and parsing happens in your browser. Your input is never sent to any server.

Edge cases and limits

  • Space: %20 vs + — encodeURIComponent uses %20. Form-encoded bodies use + for spaces. The tool uses %20.
  • Invalid percent sequences — a % not followed by two hex digits (e.g. %ZZ) is invalid and will show an error in decode mode.
  • Repeated parameters — ?a=1&a=2 is valid and shows both values in the parse table.
  • Missing protocol — the URL parser requires a protocol (https://). Without it, the URL is treated as a relative path.
  • Unicode — multi-byte characters are UTF-8 encoded before percent-encoding.

FAQ

What is the difference between URL encoding and Base64?

URL encoding escapes characters that are unsafe in URL contexts using %XX hex sequences. Base64 encodes arbitrary binary data as alphanumeric characters. They solve different problems: URL encoding preserves readability for text, Base64 is for binary-to-text conversion.

Should I encode the full URL or just the parameter values?

Encode individual values before inserting them into a URL (use encode component mode). Encoding a complete URL encodes the protocol and slashes, breaking it. Most programming languages provide separate functions for each: encodeURI vs encodeURIComponent in JavaScript.

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