Free Base64 Encoder/Decoder Tool - Convert Text, Files & Images Online

Professional Base64 encoder/decoder with advanced features including drag-drop support, batch processing, real-time conversion, and support for text, files, and images. 100% free with secure client-side processing - your data never leaves your browser.

  • Real-time encoding/decoding
  • Drag & drop file support
  • Batch processing (up to 20 files)
  • Auto-format detection
  • URL-safe Base64 support
  • 100% client-side processing
Enter plain text to encode or Base64 text to decode
0 characters | Type: Unknown
0 characters (0% size change)

Drag and drop a file here or

Maximum file size: 10MB
No file processed
Image Preview

No image selected

Drag and drop multiple files here or

Maximum 20 files, 5MB each

How to Use the Base64 Encoder/Decoder

Text Mode
  1. Enter text in the input field or paste Base64 data.
  2. Enable "Real-time processing" for automatic encoding/decoding as you type.
  3. Click "Auto" for automatic format detection, or use "Encode"/"Decode" buttons.
  4. Use "URL-safe" option for Base64 that works in URLs, or "Remove padding" to exclude = characters.
  5. Use "Sample Text" to try the tool with example data, or "Swap" to exchange input/output.
File Mode
  1. Drag and drop a file into the drop zone or click "browse" to select a file.
  2. Files up to 10MB are supported with real-time progress indication.
  3. Click "Encode File to Base64" to convert the file to Base64.
  4. To decode, paste Base64 data in the input field, specify a filename, and click "Decode to File".
Image Mode
  1. Select an image using the file input or drag and drop.
  2. Click "Encode Image to Base64" to convert the image.
  3. View the image preview and copy the Base64 string, HTML tag, or CSS code as needed.
Batch Mode
  1. Select multiple files (up to 20 files, 5MB each) using drag and drop or file browser.
  2. Review the selected files list and remove any unwanted files.
  3. Click "Encode All Files" to process all files simultaneously.
  4. View individual results in the expandable accordion or download all results as a ZIP file.

About Base64 Encoding

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's commonly used when there's a need to encode binary data that needs to be stored and transferred over media that are designed to deal with text.

Common Uses of Base64
  • Email Attachments: MIME format uses Base64 to encode binary attachments.
  • Data URLs: Embedding images directly in HTML or CSS using the data: URI scheme.
  • API Communication: Sending binary data in JSON payloads.
  • Storing Binary Data: In databases or other systems that primarily handle text.
  • Avoiding Special Character Issues: When transferring data that might contain characters that could be misinterpreted.
Base64 Characteristics
  • Base64 encoded data is approximately 33% larger than the original binary data.
  • Standard Base64 uses characters A-Z, a-z, 0-9, +, and / with = as padding.
  • URL-safe Base64 replaces + with - and / with _ to avoid URL encoding issues.
  • Base64 encoding is not encryption and does not provide any security.
All encoding and decoding is performed locally in your browser. Your data is never sent to any server, ensuring your privacy and security.

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What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's widely used in web development, email systems, and data storage to encode binary data for safe transmission over text-based protocols.

Our free Base64 encoder/decoder tool provides a comprehensive solution for all your Base64 conversion needs. Whether you're a developer working with APIs, a designer handling image data, or anyone needing to encode files for web applications, our tool offers advanced features like:

  • Real-time conversion - See results as you type
  • Drag & drop support - Easy file handling
  • Batch processing - Convert multiple files simultaneously
  • Auto-detection - Automatically identifies input format
  • URL-safe encoding - Perfect for web applications
  • Client-side processing - Your data never leaves your browser
Quick Facts
  • Character Set: A-Z, a-z, 0-9, +, /
  • Padding: = (equals sign)
  • Size Increase: ~33% larger than original
  • Use Cases: Email, JSON, XML, URLs
  • Standards: RFC 4648

Common Base64 Use Cases

Web Development

Embed images directly in CSS or HTML, encode data for APIs, and handle binary data in JSON responses. Perfect for creating data URIs and inline resources.

Email Systems

Encode attachments and binary content for MIME email messages. Essential for email protocols that only support text-based transmission.

Data Storage

Store binary data in text-based databases, configuration files, and XML documents. Ideal for systems that don't support binary data types.

Security & Authentication

Encode tokens, certificates, and cryptographic keys for secure transmission. Commonly used in JWT tokens and OAuth implementations.

Why Choose Our Base64 Tool?

Feature Our Tool Basic Tools Command Line
Real-time Processing
Drag & Drop Support
Batch Processing
Auto-detection
Mobile Friendly
No Installation Required
Privacy (Client-side)

Frequently Asked Questions (FAQ)

Base64 encoding is a method of converting binary data into a text format using a specific set of 64 characters (A-Z, a-z, 0-9, +, /). It's primarily used to:

  • Safely transmit binary data over text-based protocols (HTTP, SMTP)
  • Embed images and files directly in HTML, CSS, or JSON
  • Store binary data in text-based databases or configuration files
  • Encode data for APIs that only accept text formats

The encoding increases the data size by approximately 33%, but ensures compatibility with systems that only handle text data.

Yes, absolutely! Our Base64 encoder/decoder tool is completely safe for sensitive data because:

  • Client-side processing: All encoding/decoding happens in your browser - no data is sent to our servers
  • No data storage: We don't store, log, or track any of your input data
  • No registration required: Use the tool anonymously without creating accounts
  • HTTPS secure: The website uses SSL encryption for secure communication

Important note: Base64 is encoding, not encryption. It doesn't provide security - anyone can decode Base64 data. For sensitive information, use proper encryption before Base64 encoding.

The main differences between standard Base64 and URL-safe Base64 are:

Aspect Standard Base64 URL-safe Base64
Character 62 + (plus) - (hyphen)
Character 63 / (slash) _ (underscore)
Padding = (required) = (optional)
Use Case General purpose URLs, filenames

Use URL-safe Base64 when the encoded data will be part of a URL, filename, or any context where + and / characters might cause issues.

Our Base64 tool supports a wide range of file types and sizes:

Supported File Types:
  • Images: JPG, PNG, GIF, SVG, WebP, BMP, ICO
  • Documents: PDF, DOC, DOCX, XLS, XLSX, PPT, PPTX
  • Text Files: TXT, HTML, CSS, JS, JSON, XML, CSV
  • Archives: ZIP, RAR, 7Z, TAR, GZ
  • Media: MP3, MP4, AVI, MOV (within size limits)
  • Other: Any binary file format
Size Limits:
  • Single File Mode: Up to 10MB per file
  • Image Mode: Up to 5MB per image
  • Batch Mode: Up to 20 files, 5MB each (100MB total)

Note: Larger files may take longer to process and consume more browser memory.

After encoding an image to Base64, you can use it directly in your web pages:

HTML Image Tag:
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA..." alt="Description">
CSS Background Image:
.my-element {
    background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA...);
}
Benefits:
  • Reduces HTTP requests (faster page loading)
  • Images are embedded directly in the code
  • No external file dependencies
  • Works offline
Considerations:
  • Increases HTML/CSS file size by ~33%
  • Not cached separately by browsers
  • Best for small images (<10KB)

Yes! Base64 encoding is completely reversible. Our tool provides several ways to decode Base64 back to original files:

Text Mode:
  • Paste Base64 text and click "Decode" to get original text
  • Auto-detection feature automatically identifies Base64 input
  • Supports UTF-8 text encoding for international characters
File Mode:
  • Paste Base64 data in the decode section
  • Specify the original filename with correct extension
  • Click "Decode to File" to download the original file
Important Notes:
  • The decoded file will be identical to the original
  • File extension helps determine the correct MIME type
  • Invalid Base64 data will show an error message

Our batch processing feature offers significant advantages for handling multiple files:

Time Efficiency:
  • Process up to 20 files simultaneously
  • No need to encode files one by one
  • Progress tracking for all files
Convenience Features:
  • Drag and drop multiple files at once
  • Individual file management (add/remove)
  • Organized results in expandable sections
  • Copy individual results or download all as JSON
Professional Use Cases:
  • Web developers encoding multiple assets
  • Email systems processing attachments
  • API development with multiple file uploads
  • Data migration projects
Error Handling:
  • Individual file error reporting
  • Successful files processed even if others fail
  • Clear status indicators for each file

Yes! Once the page is loaded, our Base64 tool works completely offline because:

Client-side Processing:
  • All encoding/decoding happens in your browser
  • No server communication required for processing
  • JavaScript handles all conversions locally
Offline Capabilities:
  • Text encoding and decoding
  • File processing (all formats)
  • Image conversion
  • Batch processing
  • All tool features remain functional
Benefits:
  • Works in areas with poor internet connectivity
  • Faster processing (no network delays)
  • Enhanced privacy and security
  • Reliable performance

Note: You need internet connection only for the initial page load. After that, bookmark the page for offline access.

Technical Implementation Details

Browser Compatibility
  • Chrome 60+
  • Firefox 55+
  • Safari 12+
  • Edge 79+
  • Opera 47+
  • Mobile browsers
Technologies Used
  • Vanilla JavaScript (ES6+)
  • HTML5 File API
  • CSS3 & Bootstrap 5
  • Responsive Design
  • WCAG Accessibility
  • CSP Compatible

Performance Tips & Best Practices

Best Practices
  • Use URL-safe Base64 for web applications
  • Enable real-time processing for small texts
  • Use batch processing for multiple files
  • Compress files before encoding when possible
  • Consider file size impact (~33% increase)
  • Use appropriate MIME types for data URLs
Important Notes
  • Base64 is encoding, not encryption
  • Large files may consume significant memory
  • Mobile devices have memory limitations
  • Base64 increases data size by ~33%
  • Not suitable for very large files (>50MB)
  • Always validate decoded data integrity