URL Encoder Decoder Online: How to Encode Special Characters

If you've ever pasted a URL into a browser and watched it transform hello world into hello%20world , you've seen percent-encoding in action. URL encoding is one of those fundamentals that every developer runs into, yet it's surprisingly easy to get wrong — especially when you're dealing with query strings, form submissions, or building API clients. This guide covers everything you need to know about URL encoding and decoding: what it is, why it exists, how it works under the hood, and how to use an online URL encoder/decoder to handle special characters quickly and correctly. What Is URL Encoding? URL encoding (formally called percent-encoding ) is a method for representing characters that aren't allowed in URLs using a safe ASCII format. The URL specification (RFC 3986) defines a limited set of characters that are valid in a URL without encoding. Everything else must be encoded. The encoding format is straightforward: a % sign followed by two hexadecimal digits representing the byte v