How does Base64 encoding work?

It groups input into 3-byte (24-bit) chunks, splits each into 4 6-bit groups, and maps each to a Base64 character. Padding with '=' ensures length is multiple of 4.

When should I use Base64?

For embedding images in CSS/HTML, sending binary in JSON APIs, email attachments (MIME), authentication tokens, and data URLs.

Is Base64 encryption?

No – it's encoding, not encryption. Anyone can decode it. Use for data transport, not security.

Yes – all encoding/decoding happens in your browser. Nothing is sent to servers.

Base64 Encoder & Decoder

Q: What is Base64 encoding?

Base64 is a method to encode binary data into ASCII text using 64 characters (A-Z, a-z, 0-9, +, /). It's used to safely transmit data in text-only formats like email, JSON, or HTML.

Instantly encode text/files to Base64 or decode Base64 to text. Supports images, URLs, and file upload – fast, beautiful, and 100% private.

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Result

Characters: 0 | Size: 0 KB

How Base64 Encoding & Decoding Works

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format using 64 printable characters.

The Encoding Process Step-by-Step

Input bytes are grouped into sets of 3 (24 bits total)
Each 24-bit group is split into 4 × 6-bit segments
Each 6-bit value (0–63) maps to a Base64 character (A–Z, a–z, 0–9, +, /)
If final group is incomplete, pad with = characters to make output length multiple of 4

Example: "Man" → bytes [77, 97, 110] → 24 bits → four 6-bit groups → T W F u

Decoding Process

Reverse operation: Base64 characters → 6-bit values → combine into 8-bit bytes. Padding = is ignored.

Common Use Cases

Embedding images in HTML/CSS (data URLs)
Sending binary attachments in email (MIME)
Storing complex data in JSON
Basic authentication headers
URL-safe data transmission

Important Notes

Base64 is encoding, not encryption. It increases data size by ~33%. For security, use proper encryption.

This tool uses native browser APIs (btoa/atob) for accurate, fast processing – all client-side for privacy.

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Frequently Asked Questions

What is Base64 encoding?

Method to convert binary data to ASCII text using 64 characters for safe transmission.

How does encoding work?

Groups bytes into 3, splits into 6-bit segments, maps to Base64 characters with = padding.

When to use Base64?

Images in HTML/CSS, email attachments, JSON data, auth tokens.

Is Base64 secure?

No – it's encoding, not encryption. Easily reversible.

Is my data private?

Yes – all processing in browser, nothing sent to servers.