URL Encode / Decode
Encode or decode URL strings for web development. Convert special characters to percent-encoded format and back for safe URL transmission in any browser.
About This Calculator
Our free online URL Encode / Decode calculator helps web developers, API users, and software engineers convert text to percent-encoded format and back. URL encoding (percent-encoding) is essential for safely transmitting special characters in URLs, query parameters, and form data. Whether you're building web applications, testing APIs, debugging URL parameters, or handling internationalized resource identifiers (IRIs), this tool provides instant conversion with detailed size analysis.
The calculator uses JavaScript's built-in encodeURIComponent() and decodeURIComponent() functions that follow RFC 3986 standards. Simply enter any text in the input field, select whether you want to encode (convert text to percent-encoded format) or decode (convert percent-encoded text back to readable form), and click the button to get your result instantly. The tool also shows input/output byte sizes and overhead percentages to help understand how encoding affects data size.
URL encoding is used across multiple regions and applications worldwide. In the United States, developers commonly encode query string parameters for REST APIs and web applications. In the United Kingdom and Europe, URL encoding is essential for handling accented characters and special symbols in web addresses. In India, developers working with multilingual websites rely on percent-encoding to handle Unicode characters in regional languages like Hindi, Tamil, and Bengali within URLs.
Regional Notes
Global (US/UK/IN): URL encoding follows the same RFC 3986 standard globally. The primary differences arise in which characters need encoding — developers working with non-ASCII scripts (Devanagari, Arabic, CJK characters) will need encoding more frequently. This tool works identically regardless of region, as URL encoding is a universal web standard.
Frequently Asked Questions
What is URL encoding?
URL encoding, also known as percent-encoding, converts special characters like spaces, &, %, and # into a percent-sign followed by two hexadecimal digits (%20 for space) so they can be safely transmitted in URLs without breaking the URL structure.
Why is URL encoding necessary?
URLs can only contain ASCII characters from a limited set. Special characters like spaces, ampersands, question marks, and non-ASCII characters must be encoded to avoid breaking the URL structure and ensure proper interpretation by web servers and browsers.
What characters need URL encoding?
Common characters that need URL encoding include spaces (%20), ampersands (%26), percent signs (%25), hash symbols (%23), question marks (%3F), slashes (%2F), and all non-ASCII characters like emojis and accented letters.
What is the difference between encodeURI and encodeURIComponent?
encodeURI() encodes the full URI preserving structural characters like /, ?, &, and #. encodeURIComponent() encodes everything including structural characters, making it suitable for encoding query parameter values that may contain special characters.
How is URL decoding done in JavaScript?
Use decodeURIComponent() to decode percent-encoded URL parameter strings back to their original form, or decodeURI() to decode a full encoded URI while preserving structural characters.
Does URL encoding work the same in all programming languages?
Yes, URL encoding (percent-encoding) follows RFC 3986 and works consistently across all programming languages. JavaScript has encodeURIComponent/decodeURIComponent, Python has urllib.parse.quote/unquote, PHP has urlencode/urldecode, and Java has URLEncoder/URLDecoder — all producing compatible percent-encoded output.
When should I use URL encoding for form data?
Always encode form data when sending via application/x-www-form-urlencoded content type. This ensures special characters in form fields like spaces, &, =, and non-ASCII characters are properly transmitted to the server without corruption.
Can URL encoding handle Unicode and emoji characters?
Yes, URL encoding supports all Unicode characters including emojis. Non-ASCII characters are first UTF-8 encoded, then each byte is percent-encoded. For example, the emoji 🔗 becomes %F0%9F%94%97 in its percent-encoded form.