URL Encoder/Decoder
Encode and decode URLs and query strings
About URL Encoding
URL encoding replaces unsafe ASCII characters with a "%" followed by two hexadecimal digits. Spaces become %20, & becomes %26, and so on. This is essential for passing data in URLs.
About the URL Encoder/Decoder
URL encoding, also known as percent-encoding, is a mechanism for encoding information in a Uniform Resource Identifier (URI) under certain circumstances. The URL Encoder/Decoder on UniversalDevTools.in is a professional-grade web utility that implements RFC 3986 standards for encoding and decoding URL components, ensuring safe transmission of special characters, Unicode text, and binary data through web protocols.
When you include special characters like spaces, ampersands (&), question marks (?), or non-ASCII characters in URLs, browsers and web servers can misinterpret them, leading to broken links, security vulnerabilities, or data corruption. URL encoding solves this by converting each unsafe character into a percent sign (%) followed by two hexadecimal digits representing the character's ASCII code. For example, a space becomes %20, an ampersand becomes %26, and the Euro symbol (€) becomes %E2%82%AC.
This tool is indispensable for web developers building REST APIs, handling form submissions, constructing dynamic URLs, and working with query parameters. Whether you're encoding user input for Google Maps API requests, preparing OAuth callback URLs, constructing affiliate tracking links, or debugging malformed URLs in production logs, proper URL encoding prevents countless bugs and security issues.
The encoder uses JavaScript's encodeURIComponent() function, which encodes all characters except letters, digits, and -_.!~*'(). This is more aggressive than encodeURI(), making it perfect for encoding individual query parameters rather than entire URLs. The decoder uses decodeURIComponent() to reverse the process, with robust error handling for malformed percent-encoded sequences.
All processing occurs entirely within your browser using native JavaScript functions. Your URLs, API keys, authentication tokens, and sensitive query parameters never leave your device—critical for security-conscious developers working with production credentials or proprietary data.
features
- RFC 3986 compliant URL encoding using encodeURIComponent()
- Bidirectional encoding and decoding with instant conversion
- Real-time processing that updates as you type
- Full Unicode and international character support
- Error handling for malformed percent-encoded sequences
- Standards-compliant encoding for all special characters
- 100% client-side processing—your URLs never leave your browser
use cases
- Encoding query string parameters for GET and POST requests
- Preparing OAuth callback URLs and redirect URIs
- Constructing API endpoints with dynamic path segments
- Encoding user input for Google Maps, YouTube, and third-party APIs
- Building affiliate tracking links with campaign parameters
- Debugging malformed URLs in production application logs
- Encoding filenames and paths for cloud storage URLs (S3, GCS, Azure)
- Preparing form data for URL-encoded POST submissions
- Creating shareable links with embedded data parameters
- Encoding email addresses and usernames in URL paths
why use it
- Standards-compliant encoding prevents URL parsing errors
- Instant conversion with zero network latency
- Complete privacy—no data transmitted to external servers
- Proper Unicode handling for international characters
- Clear error messages for invalid encoded sequences
- Works offline once the page is loaded
- Free unlimited usage with no registration required
- Cross-platform compatibility on all devices and browsers
How to use the URL Encoder/Decoder
- 01Enter or paste your input
- 02Adjust the options if you need to
- 03Run the tool
- 04Copy the result
Questions
- What is URL encoding and why is it needed?
- URL encoding (percent-encoding) converts unsafe ASCII characters into a format that can be transmitted over the Internet. Characters like spaces, &, ?, and non-ASCII characters must be encoded because they have special meaning in URLs or are not allowed in URL syntax.
- What's the difference between encodeURI and encodeURIComponent?
- encodeURI encodes a full URI, preserving characters like :, /, ?, and & that are valid in URLs. encodeURIComponent encodes everything except letters, digits, and -_.!~*'(), making it ideal for encoding query parameter values. This tool uses encodeURIComponent.
- Why does a space become %20 in URLs?
- The space character (ASCII 32, hex 0x20) is not allowed in URLs. URL encoding represents it as %20 (percent sign + hex value). While + is sometimes used for spaces in query strings, %20 is the standard encoding that works everywhere in URLs.
- How do I encode special characters like & and = in URL parameters?
- Use this URL encoder tool or encodeURIComponent() in JavaScript. For example, 'name=John & Jane' becomes 'name%3DJohn%20%26%20Jane'. This prevents the & and = from being interpreted as parameter delimiters.
- Is URL encoding the same as Base64 encoding?
- No, they serve different purposes. URL encoding makes text safe for URLs by replacing special characters with %XX format. Base64 converts binary data to ASCII text. URL-encoded text is readable; Base64 text is not human-readable.