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Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 back to text instantly with file upload, auto-detect, and history

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Base64 Encoder/Decoder

Convert text to Base64 or decode Base64 back to text instantly. Upload files, auto-detect format, and save history. We do not collect or store what you enter.

Conversion Mode

Input

0 charactersDrag & drop files or Ctrl+Enter

Output

0 characters

Export Options

Conversion History (Last 20)

Keyboard Shortcuts

Ctrl+Enter Transform text
Ctrl+C Copy output (when focused)

Next step

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About Base64 Encoder/Decoder

The Base64 Encoder/Decoder is a fast, online utility for converting text to Base64 format and decoding Base64 back to readable text. Base64 encoding is essential for web development, APIs, email attachments, data URLs, and authentication headers. We do not collect or store what you enter.

Key Features

  • Encode to Base64: Convert any text to Base64 format instantly
  • Decode from Base64: Convert Base64 strings back to readable text
  • Auto-Detect Mode: Automatically detect whether input is Base64 or plain text
  • File Upload: Upload .txt, .json, .csv, or .xml files to encode
  • Drag & Drop: Drop files directly into the input area
  • Live Preview: See results instantly as you type
  • Character Counter: Track input and output character counts
  • Size Comparison: View original vs encoded file size
  • Swap Function: Quickly reverse input and output
  • Copy to Clipboard: One-click copying with visual feedback
  • Conversion History: Save last 20 conversions
  • Export Options: Download as TXT or save history as JSON
  • Keyboard Shortcuts: Ctrl+Enter to convert, Ctrl+C to copy
  • Large Text Support: Handle 100,000+ characters efficiently
  • Private: Your inputs are not collected or stored

How to Use

  1. Choose Conversion Mode: Select "Encode" to convert text to Base64, "Decode" to convert Base64 to text, or "Auto Detect" to let the tool decide automatically.
  2. Enter or Upload Text: Paste text in the input area or upload a file using the upload button or drag & drop.
  3. View Results: The converted text appears instantly in the output panel.
  4. Copy Output: Click the "Copy" button to copy the result to your clipboard.
  5. Swap Input/Output: Use the "Swap" button to reverse the input and output for quick decoding workflows.
  6. Export Results: Download the output as a .txt file or save your conversion history as JSON.
  7. Access History: Click "Show" to view your last 20 conversions and reload any previous conversion.

What is Base64?

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It uses 64 characters (A-Z, a-z, 0-9, +, /) to encode data, making it safe for transmission over text-only systems like email and HTTP headers.

Example:

Plain text: "Hello World"

Base64: "SGVsbG8gV29ybGQ="

Common Use Cases

Email Attachments

Email systems use Base64 to encode binary attachments so they can be transmitted as text.

Data URLs

Embed images directly in HTML/CSS using Base64-encoded data URLs without external files.

API Authentication

Many APIs use Base64 encoding for authentication headers and credentials.

JSON Web Tokens (JWT)

JWTs use Base64 encoding for their payload and signature components.

Configuration Files

Store sensitive data in configuration files using Base64 encoding.

Binary Data Transfer

Transmit binary data over text-only protocols like HTTP or SMTP.

QR Codes

Some QR code generators use Base64 encoding for data storage.

Database Storage

Store binary data in text-based databases using Base64 encoding.

Auto-Detect Mode Explained

The Auto-Detect mode intelligently determines whether your input is Base64 or plain text:

  • If input looks like Base64: The tool decodes it to plain text
  • If input is plain text: The tool encodes it to Base64
  • Detection is smart: Checks for valid Base64 characters and structure
  • Perfect for workflows: Quickly toggle between encoding and decoding

UTF-8 Support

This tool uses UTF-8 safe Base64 encoding, which means it can handle special characters, emojis, and non-ASCII text correctly. The encoding process uses encodeURIComponent() to ensure all characters are properly converted before Base64 encoding.

Size Comparison

Base64 encoding increases file size by approximately 33% because it uses 4 characters to represent 3 bytes of data. The tool shows you the exact size difference:

Example:

Original: 120 bytes

Encoded: 160 bytes

Increase: +33.3%

File Upload Support

You can upload text files to encode them to Base64. Supported formats:

  • .txt - Plain text files
  • .json - JSON configuration files
  • .csv - Comma-separated values
  • .xml - XML data files

You can also drag and drop files directly into the input area for quick encoding.

Conversion History

The tool automatically saves your last 20 conversions. You can:

  • View all recent conversions with timestamps
  • Click any history item to reload it instantly
  • Export your entire history as a JSON file
  • Clear history with one click

Performance Optimization

This tool is optimized for handling large text blocks:

  • Debounced Input: For text over 1,000 characters, conversions are debounced by 300ms
  • Instant Processing: Smaller text blocks are converted instantly
  • Efficient Algorithms: Uses optimized string operations
  • 100k+ Character Support: Can handle massive text blocks without freezing
  • Minimal DOM Updates: Only updates when necessary

Keyboard Shortcuts

Ctrl+Enter (or Cmd+Enter on Mac): Convert the text in the input area
Ctrl+C (or Cmd+C on Mac): Copy the output to clipboard when output area is focused

Export Options

Export as TXT

Download the converted output as a plain text file (.txt) for easy sharing or storage.

Export History as JSON

Save your entire conversion history as a JSON file for record keeping or team sharing.

Security & Privacy

Your privacy is our priority:

  • Private: Your inputs are not collected or stored
  • No Tracking: We don't track what you encode or decode

Important Note: Base64 is an encoding scheme, not an encryption method. It provides obfuscation but not security. For actual encryption, use proper cryptographic tools.

Common Errors and Solutions

Error: Invalid Base64 string

The input contains characters not valid in Base64. Make sure you're decoding actual Base64-encoded text. Base64 only uses A-Z, a-z, 0-9, +, /, and = for padding.

Error: Invalid characters for Base64 encoding

The input contains special Unicode characters. The tool handles this automatically using UTF-8 encoding, so this error is rare.

Output looks garbled

If decoding produces garbled text, the input might not be valid Base64. Try using Auto-Detect mode to let the tool determine the correct conversion.

Technical Details

Encoding Algorithm

Uses standard Base64 encoding with UTF-8 support via encodeURIComponent() for proper handling of special characters.

Decoding Algorithm

Uses standard Base64 decoding with UTF-8 support via decodeURIComponent() for proper handling of special characters.

Auto-Detection

Validates input against Base64 character set and structure. If valid Base64 is detected, the tool decodes it; otherwise, it encodes the input.

Browser Compatibility

Works in all modern browsers (Chrome, Firefox, Safari, Edge, Opera). The btoa() and atob() functions are supported in all browsers released after 2012.

Frequently Asked Questions

Is Base64 secure?

No, Base64 is an encoding scheme, not encryption. It's easily reversible and provides no security. Use proper encryption for sensitive data.

Can I encode binary files?

This tool works with text files. For binary files, you need a specialized tool that can read binary data.

How large can files be?

The tool can handle 100,000+ characters efficiently. Very large files may take a moment to process.

Is my data stored anywhere?

We do not collect or store what you enter.

What's the difference between Base64 and Base32?

Base64 uses 64 characters (A-Z, a-z, 0-9, +, /), while Base32 uses 32 characters (A-Z, 2-7). Base32 is case-insensitive and used in authenticator apps.

Browser Compatibility

This tool works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. The btoa() and atob() functions for Base64 are supported in all browsers released after 2012. All other features use standard JavaScript with universal support.

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