Base64 Encoder

Encode any text to Base64, including emoji and non-Latin scripts. Switch to the URL-safe alphabet when the result has to travel in a URL.

Your data never leaves your browser. This tool runs entirely on your device.

URL-safe alphabet

Text to encode

Base64

Enter some text to encode.

What Base64 actually does

Base64 rewrites arbitrary bytes using only 64 characters that survive systems built for text: A-Z, a-z, 0-9, plus and slash. Every three bytes become four characters, which is why the output is always about 33% larger than the input.

It exists because email, JSON, XML and URLs were designed to carry text. Putting raw binary through them corrupts the data, so it is encoded first and decoded at the other end.

3 bytes → 4 characters (33% larger)

Base64 is not encryption

This is the single most important thing to understand about it. Base64 is a reversible encoding with no key: anyone can decode it instantly, as this page demonstrates. It provides no confidentiality whatsoever.

Putting a password or an API key in Base64 to "hide" it is a real and common security mistake. If something must stay secret, it needs actual encryption.

Standard and URL-safe variants

Standard Base64 uses + and / which both have special meanings in a URL, and = padding which can be mangled by some systems. The URL-safe variant swaps + for - and / for _, and usually drops the padding.

JSON Web Tokens use the URL-safe form, which is why a JWT contains dashes and underscores but never a plus, slash or equals sign.

Frequently asked questions

Is Base64 encryption?

No. It is an encoding, not encryption. There is no key and anyone can reverse it instantly. It provides no security at all — never use it to protect a secret.

Why is my Base64 output larger than the input?

Because every 3 bytes become 4 characters, so the output is roughly 33% bigger, plus up to two characters of padding. That overhead is the cost of making binary data safe to put in text.

What do the equals signs at the end mean?

They are padding. Base64 works in blocks of three bytes, so when the input length is not a multiple of three, one or two = characters pad the final block. Many decoders, including this one, accept input without them.

What is URL-safe Base64?

A variant that replaces + with - and / with _, because those two characters have special meanings in URLs. Padding is usually dropped as well. JSON Web Tokens use this variant.

Does this handle emoji and non-English text?

Yes. The text is converted to UTF-8 bytes before encoding, which is what every other language does. Encoders built on the browser's raw btoa function throw an error on anything outside Latin-1.