Free Base64 Encoder/Decoder Online
Encode/decode Base64. Supports text, files, images with preview. URL-safe option included.
Upload File to Encode
Upload any file to convert it to Base64. Images will show a preview.
Quick Examples
What is Base64?
Base64 is an encoding scheme that converts binary data into ASCII text. It's commonly used for embedding images in HTML/CSS, transmitting data over text-based protocols, and encoding API credentials.
Features
- Encode/decode text instantly
- File upload support (any format)
- Image preview for encoded images
- URL-safe Base64 option
- Copy to clipboard
- Download results
Common Uses
- Embedding images in CSS/HTML
- Email attachments (MIME)
- JWT tokens and API keys
- Data URLs for inline content
- Transmitting binary data as text
Tips
- Use URL-safe for query parameters
- Base64 increases size by ~33%
- Upload images to get data URIs
- All processing happens locally
Privacy: All processing is done client-side; nothing you type or generate is sent to any server.
Monetization: We show light, non-intrusive ads to keep these tools free for everyone.
How It Works
- Choose Encode or Decode mode
- Enter text or upload a file
- Toggle URL-safe option if needed for URLs
- Copy or download the result
When to Use This Tool
- ✓Encoding images for CSS data URIs
- ✓Decoding JWT tokens to inspect claims
- ✓Converting API credentials for transmission
- ✓Creating inline images in HTML/CSS
Use Cases & Examples
- •Developer encoding image for inline CSS background
- •API engineer decoding Base64 response
- •Email developer creating MIME attachments
- •Web developer embedding small images in HTML
Frequently Asked Questions
What is Base64 encoding?
Base64 converts binary data to ASCII text using 64 characters (A-Z, a-z, 0-9, +, /). It is used to safely transmit binary data over text-based protocols like email or JSON APIs.
Why does Base64 increase file size?
Base64 encoding increases size by approximately 33% because it uses only 64 safe ASCII characters to represent 256 possible byte values. This overhead is the cost of text-safe transmission.
What is URL-safe Base64?
URL-safe Base64 replaces + with -, / with _, and removes padding (=) to prevent issues in URLs and filenames. Use this for query parameters or file names.
Can I encode any file type?
Yes! Upload any file (image, PDF, document, etc.) to convert it to Base64. Images will show a preview. Large files over 10MB may be slow.