What is URL Encoding? A Complete Guide for Developers

Every developer eventually runs into strange symbols in URLs — spaces turning into %20, plus signs, or entire strings that look unreadable. This process is called URL encoding. Understanding how it works is essential for web developers, API designers, and anyone working with query strings.

🔍 What is URL Encoding?

URL encoding, also known as percent-encoding, is the process of converting characters into a format that can be transmitted over the Internet. Only a subset of ASCII characters is allowed in URLs. Characters outside that set must be encoded.

For example:

Text: Hello World
Encoded: Hello%20World

Here, the space character is replaced with %20.

⚡ Why Do We Need URL Encoding?

• Safety: URLs can only contain alphanumeric characters and a few reserved symbols.
• Interoperability: Prevents misinterpretation by servers and browsers.
• Accuracy: Ensures that query parameters are transmitted exactly as intended.

✅ Reserved Characters in URLs

The following characters have special meaning in URLs and must be encoded if used literally:

📊 Example in Query Parameters

https://example.com/search?q=hello world&lang=en
Encoded URL: https://example.com/search?q=hello%20world&lang=en

🚀 Try Encoding/Decoding

You can instantly encode or decode URLs online using our free tool. It works 100% client-side, so your data never leaves your browser.

🔗 Related Tools

• Base64 Encoder / Decoder
• JWT Decoder

Mastering URL encoding ensures your apps handle parameters safely, reducing bugs and improving security.