Base64 Encoder & Decoder

This free Base64 encoder converts any text into Base64 — the encoding used for HTTP Basic authentication headers, data URIs, JWT payload segments and email attachments. The decoder reverses the process, turning a Base64 string back into readable text, and clearly reports invalid input instead of silently producing garbage.

Both directions handle the full Unicode range correctly (UTF-8), so emoji, Danish characters like æøå and non-Latin scripts encode and round-trip exactly. Everything runs locally in your browser — your data is never uploaded, stored or sent anywhere, which makes it safe for tokens, keys-in-configs you are debugging, and other sensitive strings.

Note: Base64 is an encoding, not encryption. Use it for transport and storage formats, never to protect secrets on its own.