What is Base64 Encoding? Explained with Examples

What is Base64?

Base64 is an encoding scheme that converts binary data into a set of 64 printable ASCII characters. It's used to safely transmit binary data (images, files, binary protocols) through systems that only handle text.

The 64 characters are: A–Z, a–z, 0–9, +, / (with = used for padding).

How Base64 Works

Base64 takes 3 bytes (24 bits) of input and converts them into 4 Base64 characters (6 bits each):

1. Take 3 bytes of binary data

2. Split into four 6-bit groups

3. Map each group to the Base64 alphabet

Example:

• Input: Hi (ASCII: 72, 105)
• Binary: 01001000 01101001
• Base64 output: SGk= (with = padding)

This means Base64 increases data size by approximately 33%.

Common Uses of Base64

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Base64 is NOT Encryption

This is a common misconception. Base64 is encoding, not encryption:

• It's completely reversible without any key
• Anyone who sees Base64 data can decode it instantly
• It provides zero security — it only changes the format

Do not use Base64 to hide passwords, API keys, or sensitive data.

Base64 Variants

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Quick Examples

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Decoding Base64

Base64 decoding simply reverses the process. Use our free Base64 Encoder/Decoder tool to instantly convert text to Base64 or decode Base64 back to plain text — no setup required.