Most quick Base64 snippets break on anything outside plain ASCII. This encodes as UTF-8 first, so accented letters and emoji come back out the way they went in.
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Questions
Why do other encoders break on accents?
Because the browser btoa function only accepts Latin-1. Text is converted to UTF-8 bytes here before encoding.
Is Base64 encryption?
No, and it is important not to treat it as such. Anyone can decode it — it only makes binary safe to put in text.
Other text & code tools
Everything here is free and works the same way — in your browser.