Base64 Encoder Decoder

Encode or decode any text to and from Base64.

Guides & Reference

How It Works

Encodes data to Base64 using 64 printable characters (A-Z, a-z, 0-9, +, /). Output is 33% larger than input. Used for binary data in text format.

Formula

Base64 encoding scheme

Quick Reference

Common calculations — results you can verify instantly.

Text length

Every 3 bytes

Becomes 4 Base64 chars

Size increase

Base64 overhead

~33% larger

Padding

= or == at end

Indicates byte alignment

Tips & Shortcuts

Base64 increases size by ~33%.

Never use for security or encryption. It is encoding not encryption.

Common Mistakes

Using Base64 as encryption

Base64 is trivially reversible. Anyone can decode it. Use proper encryption.

Expecting same length output as input

Output is 4/3 times input length (33% larger).

Frequently Asked Questions

Email attachments, embedding images in HTML/CSS, binary data in JSON, and API tokens.

No. It is just encoding. Never use for passwords or sensitive data.

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