URL Encoder & Decoder

URL encoding (formally called percent encoding) is a mechanism for converting characters that are not allowed — or have special meaning — in URLs into a safe text representation. Each unsafe character is replaced by a percent sign (%) followed by two hexadecimal digits representing the character's byte value. A space becomes %20, an ampersand becomes %26, and a forward slash becomes %2F.

URLs are restricted to a subset of ASCII characters defined in RFC 3986. Characters outside this set — including spaces, non-Latin letters, emoji, and many punctuation marks — must be percent-encoded before being placed in a URL. Without encoding, these characters would either be stripped, misinterpreted, or cause the URL to break entirely.

This free online URL encoder and decoder runs entirely in your browser using JavaScript's native encodeURI, encodeURIComponent, and decodeURIComponent functions. No data ever leaves your device.

JavaScript provides two encoding functions and they serve different purposes. Choosing the wrong one is one of the most common URL-handling bugs in web development.

• ▸encodeURIComponent — encodes a single component of a URL, such as a query parameter name or value. It encodes everything except A–Z a–z 0–9 - _ . ! ~ * ' ( ). This means it does encode / ? # & = : — characters that would otherwise break the URL structure if left raw inside a parameter value. Use this when building query strings.
• ▸encodeURI — encodes an entire URL and deliberately preserves the structural characters that give URLs their meaning: ; , / ? : @ & = + $ #. Use this when you need to make an arbitrary string safe as a complete URL, but still want it to remain a valid URL.

The character map in this tool color-codes exactly which characters fall into each category — green for safe (unchanged by both), rose for percent-encoded, and zinc for characters preserved by encodeURI but encoded by encodeURIComponent.

• ▸Building query strings — when appending user input to a URL as a query parameter, always use encodeURIComponent on both the key and value to prevent injection of & or = characters that would corrupt the query string.
• ▸Decoding API responses — many APIs return percent-encoded strings in URLs or Location headers. Paste them here to decode and read them in plain text.
• ▸Debugging redirect chains — URLs passed through multiple redirects often get double-encoded. Use Decode mode to peel back layers and see the original URL.
• ▸Sharing URLs containing non-ASCII text — URLs with Cyrillic, Arabic, Chinese, or emoji characters must be percent-encoded before they can be reliably shared or embedded in HTML attributes.
• ▸Form data encoding — HTML forms encode field values using a variant of URL encoding (application/x-www-form-urlencoded) before sending them. Understanding this helps when debugging POST request bodies.

Quick reference for the most commonly encountered percent-encoded characters: