URL Encode / Decode

What is URL Encoding?

URL encoding (percent encoding) converts characters that cannot be used in URLs — such as Japanese, spaces, and special symbols — into a safe %XX format. It is commonly used when submitting web forms or making API requests.

When this comes in handy

• You need to safely pass a URL containing Japanese to a browser or API: using a URL with Japanese page names or keywords as-is can sometimes cause errors. Encoding it first makes it safe to pass along.
• You have an encoded URL but can’t read what it says: decode a percent-encoded string like %E6%9D%B1%E4%BA%AC back into the original Japanese text.
• You want to check that the characters in a logged or requested URL are correct: compare the string before and after encoding to catch unintended garbling or accidental double-encoding.
• You need to handle a whole URL but aren’t sure how that differs from query-parameter encoding: this tool uses the encodeURI scheme for whole URLs. See the FAQ below if you need to encode just one query parameter’s value.

Usage examples

Example 1: Encoding a URL that contains Japanese

Input:

https://example.com/検索?q=東京 タワー&page=1

Output (encoded):

https://example.com/%E6%A4%9C%E7%B4%A2?q=%E6%9D%B1%E4%BA%AC%20%E3%82%BF%E3%83%AF%E3%83%BC&page=1

Notice that : / ? & = are preserved as structural URL characters — only the Japanese text and the space are converted to %XX form.

Example 2: Decoding an encoded URL

Input:

https://example.com/%E6%A4%9C%E7%B4%A2?q=%E6%9D%B1%E4%BA%AC%20%E3%82%BF%E3%83%AF%E3%83%BC

Output (decoded):

https://example.com/検索?q=東京 タワー

Example 3: Entering an invalid percent-encoded string

Input:

https://example.com/%ZZ

%ZZ isn’t a valid hexadecimal sequence (0-9, A-F), so decoding it produces an error:

Error: Invalid URL encoded string. Please check your input.

Check whether the characters right after a % were accidentally cut off when copying.