Tool
Base64 Encoder / Decoder
Encode any text to Base64 or paste a Base64 string to decode it back. Switch modes, copy output, or swap input and output in one click.
About Base64 Encoding
Base64 is an encoding scheme that converts binary or text data into a string of ASCII characters. It is used everywhere in computing: embedding images in HTML and CSS, encoding email attachments, storing binary data in JSON, transmitting data in URLs, and handling authentication tokens in APIs.
The encoding works by taking 3 bytes of input and converting them into 4 Base64 characters, each representing 6 bits of the original data. The resulting string is always plain ASCII — safe to include in any text-based protocol. The trade-off is size: Base64-encoded output is approximately 33% larger than the original.
Base64 is not encryption — it is trivially reversible by anyone with a decoder. Do not use Base64 to secure sensitive data. It is an encoding format for transport and storage compatibility, not a security measure.
Common use cases: data: URIs for images, Basic Auth headers (Authorization: Basic base64(user:pass)), JWT tokens (the header and payload are Base64Url encoded), and storing binary data in JSON APIs.
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