URL encode/decode

Percent-encode and decode URLs both ways.

“Component” uses encodeURIComponent (also encodes =, &, ?); “full URL” uses encodeURI (keeps URL structure characters).

You paste a link containing a non-English search term and it arrives as a trail of %EC%A0%9C. Or a query string breaks because one value contained an &. Percent-encoding is the fix, and the only real decision is how much of the string to encode.

How it works

Three buttons, two rules

Button	Underlying function	What it encodes
Encode (component)	`encodeURIComponent`	Everything unsafe, including `= & ? / :`
Encode full URL	`encodeURI`	Unsafe characters only; URL structure is left intact
Decode	`decodeURIComponent`	Turns `%XX` sequences back into characters

Use component for a single piece — one query value, a path segment, a redirect target. Use full URL when you have a complete address and want the https://, the slashes and the ? left alone.

Why the distinction matters

Encoding a whole URL with the component rule produces https%3A%2F%2F..., which is exactly right when that URL is itself a parameter value (?next=https%3A%2F%2F...) and exactly wrong when you meant to keep it clickable. Choosing the wrong one is the most common reason a link "looks encoded but doesn't work".

Decoding notes

A + is treated as a space when decoding, matching how HTML forms encode spaces. If decoding fails, the input holds a lone % or an incomplete sequence such as %E1 — often from a URL that was copied only partway. Swap moves the result into the input for a second pass, which is how you unwind a double-encoded link.

Terms explained

Percent-encoding: Replacing a byte with `%` followed by its two-digit hex value, so it can travel safely inside a URL.
Reserved characters: Characters such as `? & = / #` that carry structural meaning in a URL and must be encoded when used as data.
encodeURIComponent: The JavaScript function that encodes a single URL piece, reserved characters included.
encodeURI: The function that encodes a whole URL while leaving its structural characters usable.
Double encoding: Encoding an already-encoded string, turning `%20` into `%2520`. Decoding twice recovers it.

Frequently asked questions

Which button should I use for a query parameter?

Encode (component). A value can legitimately contain `&`, `=` or `?`, and only the component rule escapes those. Otherwise the server reads your value as the start of a new parameter.

Why did my Korean text turn into %EC%A0%9C…?

Each character is stored as several UTF-8 bytes, and every byte becomes its own `%XX` pair — three pairs per Korean syllable is normal. Pasting the encoded string into Decode gives the original text back.

Is %20 the same as +?

Almost. `%20` means a space anywhere in a URL, while `+` means a space only inside a query string, a convention from HTML form encoding. This tool treats `+` as a space when decoding, so both work here.

My decode returns an error. What now?

The input contains a broken escape — a `%` not followed by two hex digits, usually from a URL that was cut short or wrapped across lines. Recopy the full link and try again.

What is double encoding and how do I fix it?

It happens when an already-encoded value gets encoded a second time, so `%20` becomes `%2520`. Decode once to get back to `%20`, then press Swap and decode again to reach the plain text.