WebTool

URL Encoder / Decoder

Free online URL encoder and decoder following RFC3986 percent-encoding, with clear errors for truncated % sequences.

Privacy: all processing happens locally in your browser. Your input never leaves your device.

What is URL Encoder / Decoder?

URLs may only contain a limited set of ASCII characters — Chinese text, spaces, & and = must be percent-encoded before being sent as parameters. When debugging "garbled parameters" or "truncated links", the first step is decoding the URL to see its real content. This tool performs full encodeURIComponent/decodeURIComponent conversion in both directions and reports truncated % sequences with a clear error message.

How to Use

  1. Paste text to encode or an encoded URL fragment
  2. Choose encode or decode
  3. Copy the result

FAQ

Does a space encode to %20 or +?
Per RFC3986 (encodeURIComponent) a space becomes %20; in application/x-www-form-urlencoded forms the convention is +. Servers usually accept both.
Can I encode an entire URL at once?
Not recommended. encodeURIComponent would also encode : / ? — the correct approach is encoding only the parameter values.
What does the "incomplete % sequence" error mean?
The text contains a % followed by fewer than two hexadecimal characters (like %2 or %GG), usually because the encoded string was truncated.

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Last updated 2026-09-04