Question 1

What is URL encoding?

Accepted Answer

URL encoding (also called percent-encoding) is a mechanism for converting characters that are not allowed in a URL into a safe representation. Each unsafe character is replaced by a percent sign followed by two hexadecimal digits, for example a space becomes %20.

Question 2

When do I need to URL encode a string?

Accepted Answer

You need URL encoding whenever you include special characters — such as spaces, &, =, ?, #, or non-ASCII characters — inside a URL query parameter or path segment. Without encoding, these characters can break the URL structure or be misinterpreted by the server.

Question 3

What is the difference between encodeURIComponent and encodeURI?

Accepted Answer

encodeURIComponent encodes nearly all special characters (including /, ?, &, =, #) and is used for individual query parameter values. encodeURI only encodes characters that are never valid in a URL and preserves structural characters like /, ?, &, making it suitable for encoding a complete URL.

Question 4

What characters are encoded in a URL?

Accepted Answer

Characters that are not unreserved (A–Z, a–z, 0–9, -, _, ., ~) must be percent-encoded. Common examples include space (%20), @ (%40), / (%2F), : (%3A), ? (%3F), # (%23), & (%26), and = (%3D). Non-ASCII Unicode characters are first converted to UTF-8 bytes, then each byte is percent-encoded.

Question 5

How do I decode a percent-encoded URL?

Accepted Answer

Paste the percent-encoded URL into the decoder input and select Decode. The tool will replace every %XX sequence with its corresponding character, giving you the original readable string.

URL Encoder / Decoder

How URL encoding works

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