Base64 Encoder / Decoder

Base64 is an encoding scheme that turns arbitrary binary or text data into a string built only from letters, digits, and the characters `+`, `/`, and `=`. It doesn't compress or encrypt anything — it just re-represents data using a character set that's safe to embed in places that weren't designed to carry raw bytes, such as JSON payloads, URLs, email bodies, or HTML attributes. Every 3 bytes of input becomes 4 Base64 characters, which is why encoded output is roughly a third larger than the original.

This tool encodes and decodes entirely on your device using your browser's built-in text and Base64 primitives, with correct UTF-8 handling — so text containing accented characters, non-Latin scripts, or emoji round-trips exactly as expected, not just plain ASCII. Nothing you type is sent to a server, and once the page has loaded, the tool keeps working with no internet connection at all.

In practice, Base64 shows up constantly in web and API development: embedding a small image directly in CSS or HTML as a data URI, packing binary data into a JSON field, encoding credentials for an HTTP Basic Authorization header, attaching files in an email (MIME), or storing binary blobs in text-only fields like environment variables or config files. If a system complains about "invalid characters" when you try to pass binary-ish data through a text channel, Base64 is usually the fix.

It's worth being clear about what Base64 is not: it provides no confidentiality at all. Anyone can decode a Base64 string in seconds, so it should never be used as a substitute for encryption or treated as a way to "hide" sensitive data such as passwords or tokens. Use it purely as a transport-safe encoding, and rely on real cryptography (TLS, encrypted storage, signed tokens) whenever secrecy actually matters.

Switch between the Encode and Decode modes with the toggle at the top, and the tool will validate Base64 input on decode, flagging anything that isn't a well-formed Base64 string instead of silently producing garbage. Once you have a result, copy it directly or use the “Send to” button to pass it straight into another tool in this toolbox — useful, for example, when you want to check the decoded text's length or hash it.