What's the difference between Component and Full URI mode?

Component mode escapes everything except letters, digits, and - _ . ! ~ * ' ( ), use it for a single value going into a query string. Full URI mode additionally preserves : / ? # [ ] @ $ & + , ; =, so it's for encoding an entire URL without corrupting its structure.

Why did decoding fail with an error?

The input contains a malformed percent-encoding sequence, a lone % not followed by two hex digits, or an invalid escape. Fix the sequence and it will decode.

Does the swap button convert my current output back?

Yes. The swap button flips between Encode and Decode and moves the current output into the input field so you can immediately reverse the conversion.

Is any data sent to a server?

No. Encoding and decoding run entirely in your browser using native JavaScript APIs. Nothing leaves your browser.

URL Encoder & Decoder

Percent-encode or decode strings and URLs. Component mode for a single query value, full URI mode that keeps URL-structural characters intact.

Private by architecture: All processing is 100% client-side memory. Your data never leaves this browser tab.

Operation:

Mode:

Text (Input)

0 lines · 0 charsText

Encoded Output

0 charsURL

About This Tool

Percent-encodes or decodes text using the browser's native encodeURIComponent/decodeURIComponent and encodeURI/decodeURI. Component mode escapes every reserved character, so it's for a single query parameter value. Full URI mode leaves URL-structural characters (: / ? # [ ] @ $ & + , ; =) untouched, so it's for encoding a whole URL without breaking it. Conversion runs live as you type, and the swap button flips Encode/Decode while carrying the current output back into the input.

For converting a query string into a JSON object instead of just encoding/decoding text, use Query String to JSON.

Key Features

Encode / Decode operation select: swap direction instantly, with a dedicated swap button that moves output into input.
Component mode - encodeURIComponent/decodeURIComponent, for a single query parameter or path segment.
Full URI mode - encodeURI/decodeURI, preserves : / ? # [ ] @ $ & + , ; = so a whole URL stays valid.
Malformed input caught: a stray % or invalid escape sequence returns a clear error instead of throwing.
Live conversion: output updates on every keystroke; no separate submit step required.
Download output: saves the result as a .txt file.

Example

Encoding in component mode:

hello world/foo?bar=1

produces:

hello%20world%2Ffoo%3Fbar%3D1

the same input in full URI mode keeps /, ?, and = intact:

hello%20world/foo?bar=1

FAQ

What's the difference between Component and Full URI mode?: Component mode escapes everything except letters, digits, and - _ . ! ~ * ' ( ): use it for a single value going into a query string. Full URI mode additionally preserves : / ? # [ ] @ $ & + , ; =, so it's for encoding an entire URL without corrupting its structure.
Why did decoding fail with an error?: The input contains a malformed percent-encoding sequence, a lone % not followed by two hex digits, or an invalid escape. Fix the sequence and it will decode.
Does the swap button convert my current output back?: Yes. The swap button flips between Encode and Decode and moves the current output into the input field so you can immediately reverse the conversion.
Is any data sent to a server?: No. Encoding and decoding run entirely in your browser using native JavaScript APIs. Nothing leaves your browser.