URL Encoder & Decoder
Percent-encode special characters, Unicode (UTF-8) and emojis for safe URLs. Switch between encodeURIComponent (full encoding) and standard URI encoder.
URL encoding replaces unsafe characters with percent-encoded equivalents using encodeURIComponent(). A space becomes %20, an ampersand becomes %26, and the Vietnamese character "ộ" becomes the 9-character sequence %E1%BB%99. This encoding is essential when building query strings, sending form data over HTTP, or safely embedding any text containing special characters inside a URL.
Percent‑encoding & URL safety
Query string parameters with spaces/special chars — URLs cannot contain spaces or characters like &, =, #. Percent‑encoding replaces these with %20 (space) or %26 (&). Using an encoder ensures your search parameters, tracking tokens, and redirect URLs remain intact without breaking the syntax.
encodeURIComponent(str) → encodes ALL except A-Z a-z 0-9 - _ . ! ~ * ' ( )decodeURIComponent(encoded) → revert to original UTF-8 stringAPI requests with Vietnamese text — Modern APIs expect UTF-8 encoding. Strings like "Hà Nội" become H%C3%A0%20N%E1%BB%99i in percent-encoded format. Our converter handles complex diacritics, emojis, and Unicode automatically, so your REST calls, GraphQL queries, and OAuth flows never break.
Form data submission & encodeURI vs encodeURIComponent — encodeURIComponent() escapes every special character, perfect for query parameter values. encodeURI() preserves URL‑structural characters like :, /, ?, #, @ — ideal for encoding an entire URL string while keeping its schema/intact. Use our dual mode to pick the right one for your backend.
Character encoding reference table
| Original char | Percent‑encoded | Context / example |
|---|---|---|
| Space ( ) | %20 | Query parameters: q=hello%20world |
| & (ampersand) | %26 | Separate params: a=1%26b=2 |
| = (equals) | %3D | Avoid param delimiter |
| ộ (Vietnamese) | %E1%BB%99 | UTF‑8 multibyte char |
| 😀 (emoji) | %F0%9F%98%80 | Full Unicode support |
Frequently Asked Questions
What is a space in URL encoding?
A standard space character is converted to '%20' to be valid in a URL.
How many characters is 'ộ' when encoded?
The Vietnamese character 'ộ' is encoded into 9 characters: '%E1%BB%99'.
Is my API request data private?
Yes, encoding is done 100% offline in your browser. No data is sent to servers.
What does '&' convert to?
The '&' symbol converts to '%26' to prevent breaking query string parameters.
How do I convert a full URL without breaking it?
Use the 'Full URL' mode which preserves 10+ structural characters like :/?#.
What is the formula for URL Encode?
It uses the Javascript encodeURIComponent() for parameters and encodeURI() for complete URLs.