BASE64 Tool

Encode or decode text and files to Base64 instantly. Supports Image Data URI and Base64URL standards.

BaseDeck v2.0
Source Input
Raw Data
Conversion Result
encode Complete
// No output

Integrity Verified

Data processed securely. Full compliance with RFC 4648 detected.

100% Client-Side Conversion. Your data never leaves this browser.
🔒 100% Local
Fast Processing
🆓 Free Tool

Base64 Converter Use Cases

Embed images or icons directly into HTML/CSS via Data URIs
Safely transmit binary data in JSON-based API requests
Verify and debug JWT (JSON Web Token) payload segments

Frequently Asked Questions

Q. Is my data secure?

Yes, encoding and decoding are performed entirely within your browser. No data is sent to any server.

Q. What is "URL Safe" Base64?

It replaces characters like + and / with - and _ to prevent issues when used in URLs or filenames.

Q. Can I encode images?

Absolutely. You can drag and drop image files to generate Data URIs or raw Base64 strings.

Q. What is the padding (=) for?

Padding ensures the encoded string length is a multiple of 4, though some modern decoders can handle its absence.

Q. Is Base64 a form of encryption?

No, it is an encoding format for data representation, not a security measure. It can be easily reversed.

Base64 vs Base64URL

FeatureStandard Base64Base64URL
62nd Character+ (Plus)- (Minus)
63rd Character/ (Slash)_ (Underscore)
Padding (=)RequiredOptional/None
URL SafetyRequires EscapingSafe for URLs
StandardRFC 4648 (Section 4)RFC 4648 (Section 5)

⚠️ Base64URL is widely used in JWT and OAuth tokens to avoid URL encoding issues.

Data URI Size Limits

Chrome / Edge

2 MB

Firefox

32 MB

Safari

10 MB

Mobile Browsers

1 MB

Email Clients

100 KB

Use for small icons or CSS sprites to reduce HTTP requests.
Avoid for large photos to prevent blocking page rendering.
Cache encoded assets in CSS files for better performance.

" Base64 encoding increases file size by approximately 33%. "

Key Features

  • Bidirectional Real-time Encoding & Decoding
  • One-click URL-Safe Base64 Toggle
  • Support for Large Binary Files & Data URIs
  • 100% Local Privacy (No Server Uploads)

Professional Base64 tools for developers. Encode text to base64, decode base64 strings, and generate URL-safe strings instantly.

Dev Tools