The Dev Tools - Free Online Developer Utilities

Encode Mode:

URI Component (encodeURIComponent)Full URI (encodeURI)

Use URI Component encoding when encoding: query parameters, path segments, or any part of a URL that might contain special characters.

Input:

Output:

About URL Encoding

URL encoding, also known as percent-encoding, is a method to convert characters into a format that can be safely transmitted over the Internet. It replaces unsafe ASCII characters with a '%' followed by two hexadecimal digits, ensuring that URLs remain valid and data is transmitted correctly across different systems and protocols.

Understanding URL Encoding

URLs can only contain a limited set of ASCII characters. Any characters outside this set (including spaces, special characters, and non-ASCII characters) must be encoded. For example, a space becomes %20, © becomes %C2%A9, and so on. This encoding ensures that all systems can properly interpret and process the URL.

Common Use Cases

Query Parameters: Encoding values in URL query strings
API Requests: Ensuring data is properly formatted for API calls
Form Submissions: Encoding form data for transmission
File Names: Encoding file names in URLs
Internationalization: Handling non-ASCII characters in URLs

Tips

Always encode user input before including it in URLs
Use encodeURIComponent for query parameters and path segments
Use encodeURI for full URLs that may contain valid URL characters
Be aware that some servers handle + and %20 differently in query strings
Double-check encoding when handling special characters or Unicode

Encoding Modes

URI Component (encodeURIComponent): Used for encoding individual parts of a URL. Encodes all special characters including: : / ? # [ ] @ ! $ & ' ( ) * + , ; =. Best for query parameters, path segments, and fragments. Example: "hello world" → "hello%20world"
Full URI (encodeURI): Used for encoding complete URLs. Preserves URL-specific characters: : / ? # [ ] @. Best for encoding full URLs while maintaining structure. Example: "http://example.com/hello world" → "http://example.com/hello%20world"

Common Encoded Characters

Space: %20 (or + in query strings)
Plus (+): %2B
Forward Slash (/): %2F
Question Mark (?): %3F
Percent (%): %25
Ampersand (&): %26
Equals (=): %3D
Hash (#): %23

Technical Notes

URL encoding uses UTF-8 encoding for non-ASCII characters
The % character must always be encoded as %25 when used in data
Some characters have different meanings in different URL parts
Modern browsers automatically encode URLs in the address bar
Different web frameworks may handle URL encoding differently