Base64 Encoder & Decoder

About Base64 Encoding

Base64 is a group of binary-to-text encoding schemes that represent binary data in an ASCII string format by translating it into a radix-64 representation. Each Base64 character represents 6 bits of data, so 3 bytes of binary data become 4 Base64 characters.

Common Use Cases

• Email attachments — MIME uses Base64 to encode binary files for transport over text-based protocols
• Data URIs — Embed images directly in HTML/CSS: src="data:image/png;base64,..."
• API tokens — HTTP Basic Authentication encodes credentials as Base64
• JSON payloads — Safely transmit binary data within JSON strings
• JWT tokens — JSON Web Tokens use Base64URL encoding for header and payload

Base64 vs URL-safe Base64

Standard Base64 uses + and / characters which have special meaning in URLs. URL-safe Base64 (Base64URL) replaces these with - and _, making the output safe to include in URLs and filenames without percent-encoding.

Is Base64 Encryption?

No. Base64 is an encoding scheme, not encryption. It is fully reversible without any key. Never use Base64 to hide sensitive data — use proper encryption like AES instead.

Privacy

All encoding and decoding happens entirely in your browser using JavaScript. No data is transmitted to any server. This tool works offline after the page loads.