Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 to text — instantly in your browser with full UTF-8 support.
What is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that converts binary data into a sequence of 64 printable ASCII characters. It's commonly used to embed binary data in text-based formats like HTML, CSS, JSON, and email.
How Base64 Works
Base64 encoding takes every 3 bytes (24 bits) of input and splits them into 4 groups of 6 bits each. Each 6-bit group maps to one of 64 characters: A-Z, a-z, 0-9, +, and /. If the input isn't a multiple of 3 bytes, padding characters (=) are added.
Common Use Cases
- Embedding images in CSS or HTML using data URIs
- Encoding binary attachments in email (MIME)
- Storing binary data in JSON or XML
- Encoding authentication credentials (HTTP Basic Auth)
- Transferring data through text-only channels
UTF-8 Support
This tool fully supports UTF-8 characters including emojis, accented letters, and CJK characters. It first encodes the text as UTF-8 bytes, then applies Base64 encoding to those bytes.
Frequently Asked Questions
Is Base64 encryption?
No. Base64 is an encoding, not encryption. It does not provide any security — anyone can decode a Base64 string. It's meant for data transport, not data protection.
Why does Base64 make data larger?
Base64 increases data size by approximately 33%. Every 3 bytes of input become 4 characters of output, plus optional padding.
Is my data safe?
Yes. All encoding and decoding happens entirely in your browser using JavaScript. No data is ever sent to any server.
What characters are used in Base64?
Standard Base64 uses A-Z, a-z, 0-9, + (plus), / (slash), and = (equals for padding). URL-safe Base64 replaces + with - and / with _.