URL Encoder / Decoder

Percent-encoding (also called URL encoding) replaces characters that aren't safe inside a URL — spaces, ampersands, slashes, and anything outside the ASCII range — with a % followed by their hex byte value, so the result survives being placed inside a query string, path segment, or form submission without being misread as structural syntax.

Everything happens in your browser — nothing you paste here is sent anywhere. Encoding uses the browser's own UTF-8-aware APIs, so emoji and non-Latin scripts round-trip correctly rather than producing mojibake.

This is a fast way to check exactly what a query parameter value will look like on the wire, or to decode a URL pulled from a log line or browser address bar back into something readable.

encodeURIComponent vs. encodeURI

encodeURIComponent and the older encodeURI disagree on which characters they touch — encodeURIComponent escapes &, = and ? because it assumes you're encoding a single value that will be placed inside a query string, while encodeURI leaves those alone because it assumes you're encoding a whole URL that already contains them structurally. This tool encodes a component (like encodeURIComponent) — the right choice for a query-string value, not for an entire URL.

Decode treats + as a space

Decode here converts a literal + into a space before percent-decoding, matching how browsers and servers read application/x-www-form-urlencoded query strings and form bodies. That's usually what you want when decoding a query string, but if the text you're decoding genuinely contains a literal plus sign (a phone number, a math expression) rather than an encoded space, it will come out wrong — percent-encode a literal + as %2B at the source to avoid the ambiguity.