URL encoder / decoder

Component vs full URL — the bug this prevents

Component mode encodes everything reserved (= & ? / : #) and is what you want for a value inside a query string. Full-URL mode keeps the URL structure intact and only escapes characters that can't appear at all. Mixing them up produces the classics: a redirect URL whose own parameters leak into the outer URL, or a search term where & silently truncates everything after it. Spaces have two valid encodings (%20 everywhere, + only in form-encoded bodies) — when an API "loses" your plus signs, that's the collision.

Testing the encoded request against a real endpoint is one paste away — ReqPad's URL bar and param editor handle the encoding for you. See also the Base64 tool and cURL converter.