Base64 Encoder & Decoder
Encode text strings to Base64 format or decode Base64 strings to UTF-8 text in your browser.
How Base64 Encoder & Decoder Works & Technical Principles
Encode and decode Base64 character streams directly in your browser with zero server latency. All operations execute locally in a secure sandbox to guarantee complete data privacy.
Technical Overview: 6-Bit ASCII Mapping & Byte Padding
Base64 encoding partitions arbitrary 8-bit binary octets into 6-bit chunks. Each 6-bit integer maps to an index in a 64-character printable ASCII table (A-Z, a-z, 0-9, +, /), enabling binary data to travel across text-only protocols like HTTP, SMTP, and JSON.
Input & Configuration
Paste your plaintext string, binary payload, or existing Base64 encoded text into the input field.
Client-Side Processing
The browser converts Unicode characters to standard UTF-8 byte arrays and applies bitwise 6-bit index transformations.
Instant Output & Export
View the converted result instantly, toggle between standard and URL-safe modes, and copy to clipboard.
Key Capabilities & Features
Full UTF-8 & Unicode Support
Accurately processes multi-byte characters, international symbols, and emojis without encoding artifacts.
Standard & URL-Safe Variants
Toggle between standard Base64 (+/) and URL-safe Base64 (-_) formats for query strings and web tokens.
100% In-Browser Privacy Guarantee
Confidential API secrets, private keys, and authorization headers are never transmitted over the network.
Bidirectional Instant Conversion
Seamlessly switch between encoding plaintext to Base64 and decoding Base64 back to readable text.
The Base16, Base32, and Base64 Data Encodings specification (including Base64URL)
UTF-8, a transformation format of ISO 10646 standard