Base64 Encoder & Decoder

About This Online Base64 Encoder & Decoder

This free online Base64 Encoder and Decoder provides a simple yet powerful solution for converting text, files, and binary data to and from Base64 format. Whether you're embedding images in HTML/CSS, transmitting data over text-based protocols, or decoding API responses, this tool handles it all securely in your browser without sending data to any server.

Key features include:

• Text & File Support: Encode/decode plain text or upload files (images, documents, etc.) directly.
• URL-Safe Mode: Toggle for URL-safe Base64 (replaces +/ with -_, removes padding) for web usage.
• Line Wrapping: Optional wrapping at 76 characters for MIME compatibility during encoding.
• Binary Detection: Automatically detects binary data during decoding and provides file download.
• Error Handling: Validates input for invalid characters, length, and large files (up to 100MB limit).
• Copy & Download: Easily copy output or download as file with appropriate extensions.
• Theme Switching: Light and dark modes for comfortable use.
• Edge Cases Covered: Handles empty inputs, invalid Base64, multi-byte UTF-8 characters, large data, whitespace in input, and more.

What is Base64?

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format by translating it into a radix-64 representation. It uses 64 characters: A-Z, a-z, 0-9, +, and / (with = for padding). Base64 is commonly used in email attachments (MIME), data URIs for images, and API data transmission where binary data needs to be text-safe.

Note: Base64 is not encryption; it only encodes data and increases size by ~33%. For security, use proper encryption methods.

Frequently Asked Questions (FAQ)

Is this Base64 tool free to use?

Yes, this online Base64 Encoder and Decoder is completely free for all your encoding and decoding needs.

Is my data secure?

All processing happens in your browser. No data is uploaded to servers, ensuring privacy for sensitive files or text.

Can I encode/decode files like images?

Yes, upload any file for encoding to Base64. For decoding, if binary (e.g., PNG, PDF), you'll get a download option.

What is URL-safe Base64?

URL-safe Base64 replaces + with -, / with _, and removes = padding to make it safe for URLs without encoding.

What if my Base64 input is invalid?

The tool validates for correct characters and length. It handles padding automatically and shows specific errors for issues like invalid chars or mismatched length.

Does it support large files?

Yes, up to 100MB. Larger files are blocked to prevent browser issues, but most use cases are covered.

Why does decoding show binary instead of text?

If the decoded data isn't valid UTF-8 text, it's treated as binary (e.g., images). Download the file to view it.

Can I decode Base64 with newlines?

Yes, the tool automatically removes whitespace and newlines before decoding.

Is Base64 the same as encryption?

No, Base64 is encoding, not encryption. Anyone can decode it. Use it for format conversion, not security.