URL Encode / Decode

URL encoding (percent-encoding) turns spaces, non-ASCII characters, &, =, #, and other special characters into %XX so links are not truncated or misread in transit. You will need it for query strings, form posts, and callback URLs.

When to encode

If a query string has Chinese keywords, spaces, plus signs, or values that themselves contain & or =, you must encode — otherwise the server may parse fields wrong. When debugging, decode an already-encoded URL to see the real parameter values.

After you stop typing, this tool tries to detect plain text vs encoded string and convert accordingly. Whole URLs and single parameter values both work.

Encoding and the plus sign

Historically, application/x-www-form-urlencoded often used + for spaces; modern encodeURIComponent style usually uses %20. If decode looks wrong, check which convention the source system uses.

Tips

Do not re-encode an already fully encoded URL — you will get %25XX double-encoding.
Encode parameter values; usually do not mangle the whole https:// prefix.