Free Base64 Encoder & Decoder

Convert text, files, and images to Base64 instantly. URL-safe encoding, drag-drop upload, and batch processing.

URL Safe Image Support Batch Mode Secure Free Forever
0 chars Type: Unknown
0 chars
Drag & Drop File

or browse to upload

Max size: 10MB
Decode Base64 to File
Preview Image Preview

Drag multiple files here or browse

Max 20 files
Fast
Real-time processing
Secure
100% client-side
Unlimited
No file size limits
Free
No registration needed

How to Use the Base64 Encoder & Decoder

Encoding and decoding Base64 is quick and easy. Our tool offers four modes for different use cases:

  • Text
  • File
  • Image
  • Batch
  • Text Mode: Paste text or Base64 string, click Encode/Decode. Enable "Real-time" for instant conversion as you type.
  • File Mode: Drag & drop any file (up to 10MB) to convert to Base64 string. Or paste Base64 to download as a file.
  • Image Mode: Upload an image to get Base64 string, HTML <img> tag, and CSS background-image code.
  • Batch Mode: Process up to 20 files at once and download results as JSON.
100% Private: All encoding/decoding happens in your browser. Your data never leaves your device.

What is Base64 Encoding?

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, +, /) plus "=" for padding. Base64 is widely used in email (MIME), data URIs, and anywhere binary data needs to be transmitted as text.

When to Use Base64
  • Data URIs - Embed images directly in HTML/CSS
  • API Payloads - Send binary data in JSON
  • Email Attachments - MIME encoding
  • JWT Tokens - Encode header and payload
  • Credentials - HTTP Basic authentication
Base64 Limitations
  • 33% larger - Encoded data is ~33% bigger
  • Not encryption - Base64 is NOT secure!
  • No compression - Use Gzip for smaller files
  • CPU overhead - Processing adds latency
  • Cache inefficiency - Data URIs don't cache well

Common Base64 Use Cases

Image Data URIs

Embed small images directly in HTML to reduce HTTP requests. Ideal for icons and logos.

JWT Tokens

Decode JWT tokens to inspect the header and payload without verification.

Email Attachments

Email systems use Base64 (MIME) to encode binary attachments in plain text.

Frequently Asked Questions About Base64

No, Base64 is NOT encryption. It's just an encoding scheme that anyone can decode instantly. Never use Base64 to hide sensitive data. For security, use proper encryption algorithms like AES. Base64 is for data transport, not data protection.

Standard Base64 uses + and / which have special meaning in URLs. URL-safe Base64 replaces these with - and _, making it safe to use in URLs, filenames, and regex patterns. Our tool supports both with a simple toggle.

Base64 uses 6 bits per character but each ASCII character is 8 bits. So 3 bytes (24 bits) of input become 4 characters (32 bits) of output - that's a 33% size increase (4/3 = 1.33). The = padding adds slight additional overhead.

Yes, completely! All Base64 encoding and decoding happens 100% client-side in your browser using JavaScript. Your files and text are never uploaded to any server. We can't see your data even if we wanted to.

Yes! Use the File tab to encode any file type - PDFs, ZIPs, executables, documents, etc. The Base64 output can then be transmitted as text and decoded back to the original file on the receiving end.

Related Developer Tools

URL Encoder
HTML Encoder
JSON Formatter
JWT Decoder
Hash Generator
Image to Base64