Free Online Base64 Encoder & Decoder
Convert any text or data to and from Base64 format instantly - all processing happens locally in your browser. Base64 encoding is essential for safely transmitting binary data over text-based protocols such as HTTP, email, and JSON APIs.
How to Use
Type or paste your text into the input area and choose between encoding or decoding. The result updates in real-time as you type. A single click copies the output to your clipboard for use in your projects.
Common Use Cases
- Data URI Embedding: Embed images and fonts directly in HTML and CSS by converting them to Base64 data URIs, reducing HTTP requests
- API Authentication: Encode API keys and credentials for HTTP Basic Authentication headers
- Email Attachments: MIME email attachments rely on Base64 encoding for reliable text-based transmission
- JSON Serialization: Safely embed binary data within JSON payloads for API communication
- Token Handling: JWT tokens use Base64url encoding for their header and payload sections
What is Base64?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format using 64 printable characters (A-Z, a-z, 0-9, +, /). It groups 3 bytes of input into 4 Base64 characters, with = padding added for the final group when needed. Each Base64 digit represents exactly 6 bits of data, making it a reliable encoding for data transfer across systems that may not support raw binary.
Privacy Guarantee
Your data never leaves your browser. All encoding and decoding operations run entirely client-side with zero server transmission. Your sensitive content stays completely private.
Last reviewed: July 2026.