How to Convert Images to Base64 Online (and Why You'd Want To)

What is a Base64 Image?

When you convert an image to Base64, you get a long text string that encodes the raw binary data of the image. You can embed this string directly in HTML, CSS, or JavaScript — no separate image file needed.

A Base64 image URL looks like this:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA...

Why Convert Images to Base64?

• Reduce HTTP requests — Embed small icons or sprites directly in CSS, eliminating a network request
• Email templates — Many email clients block external images. Embedding as Base64 guarantees they display
• Single-file apps — Build truly self-contained HTML files with no external dependencies
• API payloads — Send images as JSON strings without multipart form encoding
• Offline-first apps — Store images in localStorage or IndexedDB as Base64 strings

When NOT to Use Base64 Images

Base64 encoding increases file size by approximately 33%. For large images, this overhead is significant:

• A 100 KB image becomes ~133 KB as Base64
• Base64 images cannot be cached separately by the browser
• They increase HTML/CSS file sizes, delaying initial page render

Rule of thumb: Only use Base64 for images smaller than 5 KB. For larger images, use a CDN or standard file references.

How to Use the Image to Base64 Tool

1. Click "Choose Image" or drag and drop any PNG, JPG, GIF, SVG, or WebP file
2. The tool instantly converts it to a Base64 data URL
3. Copy the full data URL (for use in src="" attributes) or just the Base64 string
4. Use it in your HTML: <img src="data:image/png;base64,...">

Using Base64 Images in CSS

.icon {
  background-image: url("data:image/svg+xml;base64,...");
  width: 24px;
  height: 24px;
}

Try our free Image to Base64 Converter — it runs entirely in your browser, so your images never leave your device.