URL Encode/Decode

Encode or decode special characters in URLs.

Read-only

What is URL Encode and Decode Tool?

The URL Encode and Decode Tool is a utility that simplifies the process of converting special characters for safe use in web addresses (URLs). It allows you to easily transform text containing non-URL-friendly characters (like non-English text or special symbols) into URL format, or revert encoded strings back to their original form in real-time. This tool provides essential functionality for handling form submission data, preparing API parameters, creating URL query strings, and many other web development scenarios.

What is URL Encoding?

URL encoding is the process of converting characters that don't comply with URL specifications (such as non-ASCII characters or reserved characters) into a format that web browsers and servers can safely process. Specifically, the following conversions occur:

  • Spaces are converted to %20 or +
  • Non-ASCII characters (like Japanese or Chinese text) are converted to UTF-8 encoded byte sequences in %XX format
  • Reserved characters (!, *, ', (, ), ;, :, @, &, =, +, $, ,, /, ?, #, [, ]) are converted to %XX format
  • Alphabets (a-z, A-Z), numbers (0-9), and some symbols (-, _, ., ~) remain unchanged

Features and Capabilities

  • Real-time Conversion: Instantly performs encoding/decoding as you type
  • Bidirectional Transformation: Supports both URL encoding and decoding
  • Line-by-Line Processing: Ability to process multiple lines of text at once
  • Simple Interface: Intuitive operation requires no specialized knowledge
  • Copy Functionality: Easily copy conversion results for use in applications

How to Use the URL Encode and Decode Tool

Basic Operation Steps

  1. Select Processing Mode
    Choose "Encode" or "Decode" at the top of the screen to set your desired conversion direction.
  2. Enter Text
    Type or paste the text you want to convert in the left text area.
  3. Check Real-time Results
    The conversion results will appear in real-time in the right area as you type.
  4. Copy Results
    Select and copy the converted text or click the copy button to copy the results to your clipboard.

Conversion Options

Convert Per Line

If you need to process multiple lines of text individually, enable the "Convert Per Line" option. When this option is turned on, each line is encoded or decoded independently, and results are displayed on a line-by-line basis. This is particularly useful in scenarios such as:

  • Processing multiple URL parameters separately
  • Encoding/decoding specific columns in CSV data
  • Preparing multiple API request parameters at once

Use Cases

Web Development Applications

  1. Form Data Processing
    Encoding special characters or non-ASCII text entered by users for safe transmission to servers
  2. API Request Creation
    Encoding special characters in query parameters or path parameters for REST API requests
  3. URL Query String Creation
    Encoding values to be included in URL query strings in the ?param=value&param2=value2 format

Other Practical Applications

  • Data Integration: Encoding/decoding during data transfer between systems
  • Debugging: Checking contents of encoded data and troubleshooting
  • SEO Work: Analyzing URLs and troubleshooting

Technical Background

URL encoding is primarily implemented using the JavaScript encodeURIComponent() function, which encodes specific components within a complete URI (Uniform Resource Identifier). This tool utilizes standard JavaScript functionality to achieve fast and accurate conversions.

// Encoding example
const encoded = encodeURIComponent('Hello こんにちは!');
// Result: "Hello%20%E3%81%93%E3%82%93%E3%81%AB%E3%81%A1%E3%81%AF%21"

// Decoding example
const decoded = decodeURIComponent('Hello%20%E3%81%93%E3%82%93%E3%81%AB%E3%81%A1%E3%81%AF%21');
// Result: "Hello こんにちは!"