Online Percent Encoding and Decoding Tool
Encode and decode text using standard percent encoding directly in your browser. Convert reserved characters according to RFC 3986 for free on Doffl.
About Percent Encoding
Percent encoding converts characters that are reserved or not permitted in Uniform Resource Identifiers into a standardized format. This tool allows web developers, software engineers, and digital marketers to quickly transform plain text strings into percent-encoded strings—or reverse the process to decode existing URLs.
Everything runs directly inside your web browser without sending your parameters or sensitive payloads across the network. It is completely free, requires no account setup, and provides accurate transformations compliant with RFC 3986 standards.
Key features
- Standard RFC 3986 compliant encoding and decoding
- Bidirectional conversion between raw text and percent encoding
- Full support for UTF-8 multibyte characters and symbols
- Client-side processing keeps your strings secure and private
- One-click copying of converted output to your clipboard
- Instant real-time output updates without page reloads
How to use Percent Encoding
- Paste or enter your text into the input field.
- Choose whether to encode or decode your content.
- Inspect the converted string generated in the output panel.
- Click the copy button to transfer the result to your clipboard.
Who is it for?
- Web developers preparing safe URL query parameters and path segments
- API engineers testing and debugging HTTP request headers and query values
- Digital marketers verifying encoded tracking parameters and UTM tags
- Security specialists analyzing encoded web server logs and payload strings
Frequently asked questions
What is percent encoding?
Percent encoding is a mechanism for encoding information in a Uniform Resource Identifier (URI). Characters outside the unreserved character set are replaced with a percent sign followed by their two-digit hexadecimal ASCII or UTF-8 byte value.
What is the difference between percent encoding and URL encoding?
The terms are often used interchangeably. Percent encoding is the formal term defined by RFC 3986 for URIs, whereas standard application/x-www-form-urlencoded URL encoding often replaces spaces with plus signs instead of the standard percent sequence %20.
Which characters are unreserved in RFC 3986?
Under RFC 3986, unreserved characters do not need to be encoded. These include uppercase letters (A-Z), lowercase letters (a-z), digits (0-9), and the hyphen, underscore, period, and tilde.
Does this percent encoding tool store my data?
No, your text never leaves your computer. All encoding and decoding operations take place directly in your browser using client-side JavaScript.
How does the tool handle international non-ASCII characters?
The tool converts non-ASCII characters into their corresponding UTF-8 byte sequences first, then represents each individual byte as a percent-encoded hexadecimal pair.