FAQ - URL Decoder

Why do we decode URLs?

URLs can only contain a limited set of characters from the US-ASCII charset. Characters outside this set, as well as reserved characters like ?, &, =, are percent-encoded when transmitted in URLs.

When you receive URL encoded data (from query strings, form submissions, or API responses), you need to decode it to get the original values. For example, Hello%20World needs to be decoded to Hello World before you can use it in your application.

What is URL decoding?

URL decoding (also called percent decoding) is the process of converting percent-encoded characters back to their original form. It is the inverse operation of URL encoding.

During decoding, each %XX sequence (where XX is a hexadecimal value) is replaced with the corresponding ASCII character. For example, %40 becomes @, and %2F becomes /.

What does %20 mean in a URL?

%20 is the percent encoding of the space character. When decoded, it becomes a regular space. You may also see + used to represent spaces in query strings (application/x-www-form-urlencoded format).

What does %2F mean in a URL?

%2F is the percent encoding of the forward slash (/) character. When decoded, it becomes /. This is commonly encoded when a forward slash is part of a value rather than a path separator.

What does %3F mean in a URL?

%3F is the percent encoding of the question mark (?) character. When decoded, it becomes ?. Since ? normally marks the start of query parameters, it must be encoded when used as part of a value.

Common URL encoded characters

Here are some frequently encountered encoded characters and their decoded values:

• %20 or + → Space
• %40 → @
• %26 → &
• %3D → =
• %2B → +
• %23 → #
• %25 → %