URL Encoder / Decoder
Encode special characters in URLs (percent-encoding) or decode percent-encoded URLs.
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How to use this calculator
- 1
Paste a URL or query string.
- 2
Choose encode (to percent-encode special characters) or decode (to reverse).
- 3
Use "Encode component" for individual query parameter values.
Frequently asked questions
What is the difference between encodeURI and encodeURIComponent?
encodeURI encodes a full URL, leaving characters like / : ? & = intact (they are valid URL structure). encodeURIComponent encodes everything except letters, digits, and - _ . ! ~ * ' ( ), making it safe for a value inside a query string.
Why does space become %20 or +?
In the path and query portion of URLs, space encodes to %20. In HTML form data (application/x-www-form-urlencoded), space encodes to +. This tool uses standard %20 encoding.
When do I need URL encoding?
When a URL contains spaces, non-ASCII characters, or characters with special meaning in URLs (like &, =, #). Browsers auto-encode some characters, but APIs and server-side code require properly encoded URLs.
URL encoding: making URLs web-safe
How to use the url encoder / decoder
This url encoder / decoder gives you instant, accurate results — no registration or download required. Enter your values above and get your result in seconds. The tool is free, works on all devices, and keeps your data private — nothing is stored or shared.
How the url encoder / decoder works
The url encoder / decoder uses standard formulas used in financial planning, budgeting, and investment decisions. Enter your inputs, and the tool calculates the result instantly in your browser. No server-side processing means your data stays on your device. Results update in real time as you change inputs.
Percent-encoding rules
URLs can only contain a safe subset of ASCII characters. All other characters must be percent-encoded: replaced with % followed by their two-digit hex code. Space = %20, # = %23, & = %26, = = %3D, + = %2B. Unicode characters are encoded as their UTF-8 bytes: é = %C3%A9.
Full URL vs component encoding
encodeURI is for full URLs — it preserves the URL structure (slashes, colons, question marks). encodeURIComponent is for values within URLs — it encodes everything that could break URL structure. Use encodeURIComponent when building query strings: `?q=${encodeURIComponent(searchTerm)}`.
Url encoder / decoder: how it works
Developer utilities streamline debugging, encoding, formatting, and data validation tasks. This tool is designed for engineers who need reliable, fast results without switching between applications.
Who uses this tool?
Front-end developers, back-end engineers, security researchers, and DevOps professionals use it to inspect, encode, and transform data without leaving the browser — saving context switches and copy-paste errors.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →