URL Encoder / Decoder
Encode and decode URLs with encodeURI or encodeURIComponent — all processing happens in your browser.
About URL Encoder / Decoder
URL Encoder / Decoder is a free, browser-based tool that converts text to and from URL percent-encoding using JavaScript's encodeURI or encodeURIComponent. All processing happens entirely in your browser, so the text you enter never leaves your device.
It is built for developers who need to make a value safe to put in a URL, or read back an already-encoded string. You choose encodeURIComponent to encode every special character (ideal for individual query parameters and fragments) or encodeURI to keep URL-structure characters like : / ? # & intact.
Pick a mode, then type or paste your text into the input box; the result appears instantly, with no submit step. The Swap button moves the output into the input and flips the mode, so you can encode then decode to confirm a round trip, and Copy and Clear handle the rest.
Encoding and decoding run with the browser's native functions, so nothing is uploaded to any server. If you decode malformed input, such as a stray %ZZ sequence, the tool shows an error instead of a result so you can fix the broken percent-encoding.
Frequently asked questions
- What is the difference between encodeURI and encodeURIComponent?
- encodeURIComponent encodes nearly all special characters, which is right for a single query value or fragment. encodeURI leaves URL-structure characters like : / ? # & untouched, so it suits a full URL you do not want to break.
- Is my data sent to a server?
- No. Encoding and decoding run entirely in your browser using native JavaScript functions, so the text you enter is never uploaded anywhere.
- Why does decoding show an error?
- Decoding fails when the input contains invalid percent-encoding, for example an incomplete or malformed sequence like %ZZ. Check the highlighted input and correct the broken escape sequence.