toolkit

Base64 Decoder

Runs in browser

Decode Base64 back to text

How to Use

Enter text to encode or Base64 to decode. Toggle tabs to switch modes.

You will see:

  • Instant Conversion
  • Copy-ready Output
  • Error Validation
  • Safe Local Processing
Decoded Text

No output yet

Enter Base64 and click Decode

About Base64 Decoding

Base64 decoding converts Base64-encoded text back to its original binary or text form. This is essential for reading encoded API responses, email attachments, and data URLs.

Common Decoding Scenarios

  • JWT Payloads: Decode token claims for debugging
  • API Responses: Some APIs return Base64-encoded data
  • Email Attachments: MIME uses Base64 for binary files
  • Data URLs: Extract embedded images or files
  • Config Files: Decode secrets in configuration

Base64 Variants

Standard:
Uses +/ and = padding
URL-safe:
Uses -_ instead of +/ (no padding)
MIME:
Line breaks every 76 characters

⚠️ Important Notes

  • Base64 is encoding, not encryption — anyone can decode it
  • Invalid Base64 will fail to decode — check for proper padding
  • Binary data may not display correctly as text

💡 Pro Tips

  • Use this to inspect JWT tokens without a special decoder
  • Try URL-safe decoding if standard decoding fails
  • For binary data, download as file instead of viewing
  • This tool processes everything locally in your browser

Further Reading