encodeURI vs encodeURIComponent?

encodeURI preserves URL-reserved characters (:/?#&=); encodeURIComponent encodes them all. Use encodeURIComponent (this tool) for a parameter value, encodeURI for a full URL.

Why %20 not + for space?

In modern URLs (RFC 3986), a space encodes to %20. + is an older convention from HTML forms. Both may appear in the wild.

Developer

URL encoder / decoder

Encode special characters in a URL (spaces, accents, ?, &, #…) or decode them. Based on encodeURIComponent.

Original text

Encoded

Uses encodeURIComponent (every reserved character is encoded except letters, digits and - _ . ~).

How to use this tool

URLs can't contain certain characters (spaces, accents, {}, <>, etc.) without percent-encoding. Encoding turns "hello world?" into "hello%20world%3F". Useful to build URLs manually, debug a request, understand a GET parameter, or paste an accented link into a strict system.

Concrete examples

"hello world" → "hello%20world"
"café & tea" → "caf%C3%A9%20%26%20tea"
"?q=search" → "%3Fq%3Dsearch"

Frequently asked questions

encodeURI vs encodeURIComponent?: encodeURI preserves URL-reserved characters (:/?#&=); encodeURIComponent encodes them all. Use encodeURIComponent (this tool) for a parameter value, encodeURI for a full URL.
Why %20 not + for space?: In modern URLs (RFC 3986), a space encodes to %20. + is an older convention from HTML forms. Both may appear in the wild.