URL Encoder / Decoder

URL encoding (percent-encoding) converts characters that are not allowed in URLs into a %XX hex format. For example, a space becomes %20 and an ampersand becomes %26. Use Component mode for individual query string values (encodes & = + ?), or Full URL mode to encode a complete URL while preserving its structure. All processing runs locally in your browser.

Tip: Press Ctrl+Enter to run

Output
Result will appear here…
Common URL encoding reference
Space → %20 (component) / + (form) ! → %21 " → %22 # → %23 $ → %24 % → %25 & → %26 ' → %27 ( → %28 ) → %29 * → %2A + → %2B , → %2C / → %2F : → %3A ; → %3B = → %3D ? → %3F @ → %40 [ → %5B ] → %5D

What this tool does

URLs can only safely contain a limited set of ASCII characters. Spaces, ampersands, equals signs, and non-ASCII text must be percent-encoded — replaced with % followed by two hex digits — to be transmitted correctly. This tool encodes or decodes URL strings entirely in your browser. Nothing is sent to a server.

How to use it

  • Select Encode or Decode and paste your URL or query string value.
  • Click Process or press Ctrl+Enter.
  • Use Swap to move the output back into the input for chained operations.
  • Refer to the quick reference table in the tool for common character mappings.

Characters that need encoding and why

  • Space → %20 — Spaces are not valid in URLs.
  • & → %26 — Separates query parameters. Literal ampersands in values must be encoded.
  • = → %3D — Separates keys from values. Encode when it appears inside a value.
  • + → %2B — Treated as a space in form-encoded query strings. Encode when you mean a literal plus sign.
  • # → %23 — Marks the fragment; everything after it never reaches the server.
  • Non-ASCII — UTF-8 encoded first, then each byte percent-encoded. "café" becomes caf%C3%A9.

Frequently Asked Questions

What is the difference between encodeURI and encodeURIComponent?

encodeURI encodes a complete URL, leaving structural characters (/, ?, &, #) intact because they're needed for the URL to function. encodeURIComponent encodes a single value — a query parameter or path segment — and encodes those structural characters too. For dynamic values going into query strings, always use the component variant.

What is double-encoding and how do I avoid it?

Double-encoding happens when you encode something that's already encoded — turning %20 into %2520 because % gets encoded to %25. The fix: only encode once, just before the URL is used. If you receive an already-encoded URL, decode it first before re-encoding.

Why does a + in a decoded URL show up as a space?

HTML form submissions use application/x-www-form-urlencoded format, where spaces become + rather than %20. Server-side form parsers decode + as a space. Standard percent-encoding uses %20 for spaces. Mixing the two conventions in the same query string causes this confusion.

Want the full explanation? Read the guide: Why URL Encoding Trips Up So Many Developers →