URL Encoding Guide: What It Is and How to Encode URLs Online

What is URL Encoding?

URL encoding (also called percent-encoding) is the process of converting characters that are not allowed in URLs into a safe format. Each unsafe character is replaced by a percent sign (%) followed by two hexadecimal digits representing the character's ASCII code.

For example, a space becomes %20, and an ampersand becomes %26.

Why Do URLs Need Encoding?

URLs can only contain a limited set of characters defined by the URI specification (RFC 3986). Characters outside this set — including spaces, non-ASCII characters, and many punctuation marks — have special meaning or would break URL parsing. Without encoding, a URL containing a search query like Hello World & More would be ambiguous or invalid.

Which Characters Must Be Encoded?

Characters are divided into three groups:

• Reserved characters — have special meaning in URLs (: / ? # [ ] @ ! $ & ' ( ) * + , ; =). Encode these when they appear as data values, not URL structure.
• Unreserved characters — always safe to use as-is (A–Z a–z 0–9 - _ . ~)
• Everything else — must be percent-encoded, including spaces, non-ASCII characters, and special symbols

URL Encoding vs encodeURI vs encodeURIComponent

JavaScript provides two built-in functions for this:

• encodeURI() — encodes a full URL but preserves reserved characters like ://?&=
• encodeURIComponent() — encodes everything including reserved characters; use this for query parameter values

To encode a query parameter value safely: encodeURIComponent("hello world & more") → hello%20world%20%26%20more

Common Encoded Characters

• Space → %20 (or + in form data)
• & → %26
• = → %3D
• + → %2B
• / → %2F
• ? → %3F
• # → %23

How to Encode / Decode a URL Online

1. Open the ToolsPal URL Encoder
2. Paste your URL or query parameter value in the input
3. Encoded output appears instantly on the right
4. Switch to Decode to convert percent-encoded text back to readable form