URL Decoder Developer
Turn percent-encoded text back into readable characters.
URL Decoder is a free online tool that turn percent-encoded text back into readable characters. It runs entirely in your web browser using plain JavaScript, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.
- Price
- Free: no account, no quota, no watermark
- Category
- Developer
- Where it runs
- In your browser, on your device
- Files uploaded
- None
- Technology
- plain JavaScript
- Settings
- None, it just works
- Works offline
- Yes, after the first visit
About URL Decoder
Decoding turns each `%XX` sequence back into the byte it names, then interprets the result as UTF-8. That last step is where things break: a URL encoded in a legacy character set produces byte sequences that are not valid UTF-8, and decoding throws rather than guessing. Double-encoded URLs (where `%` was itself encoded as `%25`) decode one layer at a time, so run it twice.
How to use it
- Paste the text you want to run through url decoder.
- There is nothing to configure: the result updates as you type.
Under the hood
| Runs on | plain JavaScript: runs the whole thing |
Questions
Why did decoding fail with a malformed URI error?
The input contains a `%` that is not followed by two hexadecimal digits, or a byte sequence that is not valid UTF-8. A lone `%` in otherwise plain text is the most common cause.
How do I tell if a URL is double-encoded?
Look for `%25`: that is an encoded percent sign, which almost always means an already-encoded URL was encoded again. Decoding twice fixes it.