Kastavo

Base64 Converter

Pick encode or decode, paste the content, and see the result update in real time.

Processed locally in your browser.

How it works

Base64 is a way to represent binary data as text using only letters, numbers, and two extra symbols — used in e-mail attachments, embedded image URLs (data URIs), auth tokens, and APIs. This tool handles accents, emoji, and any Unicode character correctly: internally, text is converted to UTF-8 bytes before becoming Base64, avoiding the common "btoa breaks accents" problem you get from calling the browser's native function directly. If the pasted content isn't valid Base64, or decodes to something that isn't valid UTF-8 text, the tool flags it instead of showing a corrupted result.

Frequently asked questions

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