URL Encode & Decode Online — Bidirectional Real-time Tool
encodeURIComponent · encodeURI · RFC 3986 — Query Params Table · URL Builder · Batch Mode — 100% browser-side
Paste text → get encoded URL
Real-time · 200ms debounce · No button click needed
The complete URL encoding toolkit — encode and decode in one place with real-time results. Switch between encodeURIComponent, encodeURI, and RFC 3986 modes. Use the Swap button to instantly reverse direction. Batch mode handles 10+ URLs simultaneously. Code snippets for JS, Python, and cURL included.
What is URL Encoding?
URL encoding (percent encoding) converts special characters into a % followed by two hex digits. For example, a space becomes %20, & becomes %26, and / becomes %2F. This ensures URLs remain valid across all browsers, servers, and APIs regardless of the special characters they contain.
encodeURIComponent vs encodeURI vs RFC 3986
encodeURIComponent is the safest choice for encoding individual query parameter values — it encodes everything except A-Z a-z 0-9 - _ . ! ~ * ' ( ). encodeURI is designed for full URLs and preserves characters like : / ? # [ ] . RFC 3986 is the strictest standard — also encoding ! ' ( ) * — recommended for OAuth signatures and API authentication headers.
Frequently Asked Questions
What does bidirectional mean?
Bidirectional means the tool encodes AND decodes in one place. Switch direction with the toggle buttons or press S key to swap input and output instantly.
Does the encoding happen in real-time?
Yes. The output updates 200ms after you stop typing — no button click needed. This follows CalcNation's developer tool standard for instant feedback.
What is the Diff View?
Diff View highlights the characters that were encoded in amber. Hover any %XX token to see what character it represents. This helps you understand exactly what changed.
What encoding mode should I use by default?
For encoding individual query parameter values: use encodeURIComponent (default). For encoding a full URL while keeping its structure: use encodeURI. For OAuth and API signatures: use RFC 3986.
Does the tool work offline?
Yes. All encoding and decoding logic runs in your browser using JavaScript's built-in encodeURIComponent and decodeURIComponent functions. No server calls are made for any operation.