Overview
URL-encode or decode text for safe transport in query strings, form bodies, and redirects. This tool follows encodeURIComponent semantics (ideal for query parameters). Runs locally in your browser.
Pro time-savers
- Batch encode/decode (per line)
Use cases
- Encode a query parameter value containing spaces, Unicode, or reserved characters.
- Decode a percent-encoded callback URL to inspect its real contents.
- Fix double-encoded values (e.g. %2520) by decoding step-by-step.
Common pitfalls
- If you encode a full URL with encodeURIComponent, you’ll also encode : / ? & and break it. Use encodeURI for full URLs.
- Plus-sign (+) is sometimes used for spaces in query strings; decodeURIComponent does not treat + as space automatically.
- Double-encoding (%25...) is common when values pass through multiple layers. Decode step-by-step.
FAQs
encodeURI vs encodeURIComponent — which should I use?
Use encodeURIComponent for query parameter values. encodeURI is for an entire URL and won’t encode reserved characters like :, /, ?, &.
Why does decode throw an error?
The input likely contains invalid or incomplete percent-encoding (e.g. a truncated %E4). Make sure the string is complete.
Why do I see %2520 instead of %20?
That’s double-encoding. Decode once to get %20, then decode again to get a space.
Does this change + into space?
In query strings, + is sometimes used for spaces. If your data uses that convention, replace + with space before decoding.
Examples
Input
hello world
Output
hello%20world