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Tools / Base64 Encoder/Decoder

Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 strings instantly. Perfect for APIs, authentication, and data transmission.

Free Tool
0 B
Input Size
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Output Size
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Size Increase
What is Base64?
Base64 is a way to encode binary data using only 64 ASCII characters. It's commonly used in APIs, email attachments, and data URLs. The encoded size is typically 33% larger than the original.

When to use Base64 encoding

Base64 encoding is useful when you need to transmit binary data over text-only channels like email or HTTP headers. It's also used for embedding images in HTML/CSS as data URLs, storing credentials in API authentication headers, and transmitting files through JSON APIs that don't support binary data directly.

Understanding Base64 size increase

Base64 encoding increases the size of data by approximately 33% because it uses 6 bits per character instead of 8. This is a tradeoff for compatibility and safety. For large files, consider using actual binary transmission methods instead of Base64. However, for small text, credentials, and configuration data, Base64 is the standard.