What's Often Hiding in a Base64 String
Since Base64 shows up in authentication headers, API tokens, and JWTs, a string you're decoding to inspect might actually contain credentials or session data — and a string you're encoding might be a password or key you're about to embed somewhere. If an online converter uploads that text to a server just to perform the conversion, that data leaves your device in the process.
How This Tool Keeps Everything Local
This Base64 Encoder / Decoder runs entirely in JavaScript, inside your own browser tab. The conversion — in either direction — happens on your device, using your browser's own built-in encoding capabilities. Nothing you type is sent to a server. This is verifiable, not just a stated claim.
- Check the Network tab: open your browser's developer tools, watch the Network panel, and convert some text — you won't see it uploaded anywhere.
- Disconnect from the internet after the page loads, and convert anyway — it still works, since no server round-trip is involved.
Worth Remembering: Base64 Itself Isn't Protection
Client-side processing protects the data while you're using this tool — but it's worth being clear that Base64 encoding itself provides no security once you've generated it. Anyone who later obtains that Base64 string can decode it instantly with no special access required. If what you actually need is genuine protection (not just text-safe representation), Base64 alone isn't the tool for that — a proper encryption tool with a passphrase is.
Need to convert sensitive text without uploading it anywhere?
Convert Base64 Safely