Safely encode or decode URL strings for API and web requests instantly. Advanced percent-encoding tool with Strict (Params) and Loose (URI) component settings.
DEVELOPER TIP: Use Strict Mode (encodeURIComponent) when encoding a single query parameter value. Use Loose Mode (encodeURI) when encoding an entire, complete URL string so it doesn't break the http:// protocol.
If you have ever copied a link from your browser's address bar and pasted it into a chat, only to see it magically turn into a massive string of %20 and %3F characters, you have witnessed URL Encoding in action. But why does the internet do this?
Web addresses (URLs) can only be sent over the internet using the standard ASCII character-set. If your URL contains unsafe characters—like spaces, brackets, emojis, or symbols like & and =—the web server might misinterpret them. For example, if you send an API request with a space in it, the server will think the URL has ended and will throw a 404 Error. URL Encoding (also known as Percent-encoding) solves this by safely converting these problematic characters into a globally accepted format.
This is where our PRO tool completely outshines basic online converters. In JavaScript, there are two distinct ways to encode a URL, and using the wrong one will instantly break your web application.
encodeURIComponent): You should use this when you are encoding a single piece of data that you want to attach to the end of a link. This mode is ruthless. It encodes almost everything, including /, ?, &, and =. If you try to pass an entire URL through this, it will completely destroy the https:// part, making the link unclickable.encodeURI): You should use this when you want to encode an entire, full URL. It is smart enough to leave the structure of the link (like the slashes and colons) completely untouched, while only encoding the unsafe characters like spaces and emojis.Our tool features a simple dropdown menu allowing you to toggle between these two crucial algorithms instantly.
Just like our encoding engine, we built an incredibly robust URL Decoder. As a developer, you will frequently pull raw data from databases, webhooks, or UTM parameters in Google Analytics. If you need to read this data locally, it looks like a garbled mess of percent signs.
By switching our tool to "Decode URL" and pasting the encoded string, our client-side parser instantly reconstructs the safe entities back into their raw, readable format. If you accidentally paste a broken or malformed string (which normally crashes a JavaScript application), our tool uses a safe try/catch block to catch the error and alert you gracefully.
If you manage web properties, you will use this tool for several high-level tasks:
Is my data uploaded to your servers during encoding?
Absolutely not. Our URL Encoder PRO relies exclusively on a Client-Side JavaScript engine. The entire conversion process happens directly inside your browser. No strings or API keys are ever transmitted over the internet.
Why is a space converted to %20 instead of a plus sign (+)?
This is a historical quirk of web development! According to modern RFC 3986 standards, spaces in a URL path should be encoded as %20. The plus sign (+) is an older standard typically used only for spaces inside the query string (the part after the ?). Our tool uses the strict, modern %20 standard to guarantee maximum compatibility across all modern web servers.