Online URL Decoder Tool

Convert percent-encoded strings back to human-readable text instantly and securely.

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How URL Decoding Works

URL Decoding is the process of reverting percent-encoded characters back to their original form. Browsers do this automatically when you visit a URL, but developers often need to decode query parameters manually when working with APIs or backend data.

For example, when a form submits a space as %20, the URL Decoder reads the hexadecimal value 20 and converts it back to a space character.

Common Decoding Examples

Encoded Input Decoded Output
Hello%20World Hello World
price%3D100%26currency%3DUSD price=100&currency=USD
user%40urlencoder.com user@urlencoder.com
%E3%81%93%E3%82%93%E3%81%AB%E3%81%A1%E3%81%AF こんにちは

Frequently Asked Questions about URL Decoding

It takes a string that has been URL encoded (percent-encoded) and converts all the %XX sequences back into their original characters. This makes the string readable by humans.

This error occurs when you attempt to decode a string that contains an invalid percent-encoded sequence (e.g., a "%" that is not followed by two valid hexadecimal digits). Ensure your input string is fully and correctly encoded.

What is URL Decoding?

URL decoding is the process of translating a machine-safe, percent-encoded string back into human-readable text. It is the exact opposite of URL encoding.

When a web server or application receives data from a URL (such as a search query containing %20 instead of a space), it must decode that data to process it correctly.

How URL Decoding Works

A decoder scans the text for the percent sign (%). When it finds one, it reads the next two hexadecimal characters, looks up their corresponding ASCII or UTF-8 value, and replaces the three-character sequence (e.g., %40) with the original character (e.g., @).

How to Decode a URL

  1. Paste your encoded string: Insert the percent-encoded URL or text into the input box.
  2. Select the decoding mode: Usually, "Decode URI Component" is the right choice for decoding query parameters or specific data fields.
  3. Click Decode: The tool will instantly process the input and display the human-readable result.
  4. Copy the output: Use the copy button to save the decoded text to your clipboard.

URL Encoder vs URL Decoder

Use a URL Encoder before sending data over the internet to ensure it is transmitted safely without breaking the URL structure.

Use a URL Decoder after receiving data (like an API payload or a complex web address) to translate it back into a usable format for your database, application logic, or human review.

Common Decoding Errors

  • Malformed Sequences: If a URL contains a % followed by invalid hexadecimal characters (e.g., %ZZ), the decoding process will fail (often resulting in a URIError in JavaScript).
  • Double Decoding: Decoding a string that has already been decoded can lead to data loss or corruption, especially if the original data contained a literal %.