Base64 Encoder & Decoder Online
Base64 is a way of turning any text, or any binary data, into a safe string made only of letters, numbers and a few symbols. It is used everywhere on the web: email attachments, images embedded in web pages, API tokens, and data passed inside URLs all rely on it. The reason is simple. Ordinary text can contain characters that break a system, such as line breaks, quotes or non-English letters, but a Base64 string contains only the characters A to Z, a to z, 0 to 9, plus, slash and the equals sign used for padding. That makes it safe to paste into places that only accept plain ASCII text. This free Base64 encoder and decoder converts your text in both directions, instantly and entirely in your browser, so nothing you type is ever uploaded or stored. One thing this tool gets right that many simple encoders do not is UTF-8 handling. Text is not just the letters on an English keyboard: it includes accented characters like é, symbols like €, and emoji like 😀.
Those characters are stored as several bytes in UTF-8, and an encoder that ignores that will produce broken output or an error. This tool encodes the UTF-8 bytes correctly, so "café" and "Hello, World!" both round-trip perfectly: encode them, decode the result, and you get back exactly what you started with. Developers use Base64 to embed small images in CSS, to send credentials in an HTTP Authorization header, and to store binary data in JSON, which cannot hold raw bytes. If you have ever seen a long string ending in one or two equals signs, you have almost certainly seen Base64.
Base64 Result
Enter text above and click Encode or Decode.
What Is Base64?
Base64 is an encoding scheme, not an encryption method. It takes three bytes of data at a time and represents them as four characters from a 64-character alphabet. Because three bytes are 24 bits and each Base64 character carries 6 bits, four characters hold exactly the same information as three bytes. When the input length is not a multiple of three, equals signs are added as padding at the end: one equals sign when two bytes are left over, two when only one byte remains. That is why Base64 output is about a third longer than the input. The output is still plain text, which is the whole point: a system that only accepts text can now carry binary data safely, and anyone can decode it back to the original bytes.
Base64 Is Not Encryption
It is important to be clear about this: Base64 does not hide your data. Anyone who sees a Base64 string can decode it in seconds, with no key and no password. It is designed for safe transport, not for secrecy. That means you should never encode a password, a private key or a secret token in Base64 and treat it as protected. It is fine for embedding an image in a web page, for sending a file through an email system that only handles text, or for putting binary data inside a JSON document. For anything that must stay secret, use real encryption, and keep the encrypted result and its key separate. This tool also never sends your text anywhere, but the Base64 output itself is as readable as the input to anyone who decodes it, so treat it the same way you would treat the original text.
How to Use
- Type or paste your text into the box. It can be a word, a sentence, a paragraph or a block of code, in any language.
- Click Encode to Base64. The encoded result appears below, using the standard Base64 alphabet with equals-sign padding where needed.
- Click Decode from Base64 to reverse it. Paste a Base64 string instead of plain text, and the tool returns the original text, decoding the UTF-8 bytes correctly.
- Click Copy Output to copy the result. If the input is not valid Base64, the tool shows an error instead of guessing, so you will know immediately that something is wrong.
Worked Example
Enter the text Hello, World! and click Encode. The result is SGVsbG8sIFdvcmxkIQ==. The two equals signs at the end are padding, because "Hello, World!" is 13 bytes long and 13 is not a multiple of three. Now paste SGVsbG8sIFdvcmxkIQ== back into the box and click Decode, and you get Hello, World! again, exactly as it started. Try a non-English example too: encoding café gives Y2Fmw6k=, because the letter é is two bytes in UTF-8 and the encoder handles those bytes correctly. A string that is not valid Base64, such as not!base64***, shows an error message instead of a wrong result.
Frequently Asked Questions
Is Base64 the same as encryption?
No. Base64 is an encoding that anyone can reverse without a key or password. It is meant to make data safe to transport through text-only systems, not to keep it secret. Never treat a Base64 string as protected.
Why does Base64 output end with equals signs?
The equals signs are padding. Base64 works in groups of three bytes, so when the input length is not a multiple of three, one or two equals signs are added to make the output length a multiple of four characters.
Does this tool handle emoji and accented characters?
Yes. The tool encodes text as UTF-8 bytes before converting to Base64, and decodes the bytes back to UTF-8 afterwards, so characters like é, € and emoji round-trip correctly.
What is Base64 used for?
Common uses include embedding images in HTML and CSS, sending email attachments, storing binary data in JSON, and passing tokens and credentials in HTTP headers. Anywhere a system accepts only plain text, Base64 lets binary data travel safely.
Is my text private when I use this encoder?
Yes. All encoding and decoding runs in your browser, and your text is never uploaded, stored or shared. Closing the page removes it completely.