URL Encoder / Decoder

URL encoding is a quiet necessity of the web. Every query string, form submission, and API call depends on percent-encoding to safely carry spaces, unicode, and special characters inside a URL. A reliable URL encoder is essential for API developers, marketers building tracking links, and anyone debugging why a link broke.

OpenToolLab's URL tool handles the two encoding modes developers actually need: encodeURIComponent for query parameters and form data, and encodeURI for full URLs. Decode mode reverses percent-encoding, and the query string parser automatically detects key-value pairs so you can read exactly what a URL is carrying.

Everything updates live as you type, which makes the tool perfect for debugging — paste a messy tracking URL and watch it decode before your eyes. And like every OpenToolLab tool, it runs entirely in your browser. Your links and text never leave your device.

Why does URL encoding even exist? URLs are governed by RFC 3986 and only allow a limited set of safe characters: letters, digits, and a small group of symbols like -, _, ., and ~. Everything else — spaces, quotes, parentheses, ampersands, non-ASCII text — must be converted into a percent sign followed by two hexadecimal digits. A space becomes %20, an ampersand becomes %26, and the string 'hello world' becomes 'hello%20world'. Without this transformation, browsers would truncate, misread, or reject links that contain special characters.

The two encoding modes solve different problems, and mixing them up is a classic bug. encodeURIComponent encodes every reserved character, including &, =, ?, and /, making it the correct choice for individual query parameter values. encodeURI leaves those reserved characters intact, so it is used for whole URLs. This tool exposes both modes clearly, so you can encode a full link or just a single parameter value without guesswork.

Decoding is equally important, especially when debugging. A tracking URL or analytics redirect is often double-encoded, and reading it raw is nearly impossible. Paste it into the decoder and the tool percent-decodes the string and breaks out key-value pairs, so you can see exactly which parameters the link carries and what each value means. That single step turns an unreadable string into an audit you can actually follow.

Developers switching between languages will find the encoding rules consistent. JavaScript's encodeURIComponent, Java's URLEncoder, and Python's urllib.parse.quote all implement the same percent-encoding standard, so the output you see here matches what your code produces. That makes this tool a handy cross-check when you are debugging why a URL built in one language breaks in another.