Base64 Encoder & Decoder

What is this?

A high-performance client-side Base64 utility that supports bi-directional encoding and decoding for plain text, UTF-8 strings (including non-Latin characters and emojis), URL-safe variants, and file-to-Base64 Data URI conversions. Built with native browser Web APIs for instant processing.

Key Features & Concepts

• Bi-Directional Operation: Easily switch between Encode and Decode modes with automatic input detection
• Full UTF-8 / Unicode Support: Encodes emojis, accent marks, and foreign languages without character corruption
• URL-Safe Base64 Variant: Option to swap "+" with "-" and "/" with "_" for safe URL query inclusion
• File & Image to Base64 Data URI: Drag and drop images, PDFs, or documents to convert them to Base64 data URIs
• Live Byte Diagnostics: View input string size, encoded output size, and expansion ratio (+33% typical)
• One-Click Actions: Swap input/output, copy output, clear editor, or download output as text
• Error Handling: Gracefully flags invalid Base64 input strings with corrective guidance
• 100% Client-Side Processing: Zero server uploads, ensuring complete privacy for keys and passwords

How to Use

1. Select your desired mode: "Encode" or "Decode" (or upload a file).
2. Type or paste your input text into the input panel.
3. To encode UTF-8 text with special characters or emojis, keep the "UTF-8 Mode" toggle enabled.
4. To generate URL-safe Base64 strings, toggle "URL-Safe Mode".
5. For file encoding, drop an image or document onto the file upload drop zone to generate a Base64 Data URI.
6. Click "Copy Output" to copy the result to your clipboard.

Common Use Cases

• Web Developers creating inline CSS data URIs for fonts and SVG icons
• Security Engineers inspecting Basic Auth headers and API token headers
• Full-Stack Engineers encoding binary data for JSON payload transport