What Is Base64 Image Encoding?
Base64 is an encoding scheme that converts binary data (like an image file) into a string of ASCII text characters. This encoded string can be embedded directly in HTML, CSS or JSON, eliminating the need for a separate image file request.
What Is a Data URI?
A Data URI (Data URL) is a URI scheme that allows embedding small files inline in web pages. For images, it looks like: data:image/png;base64,iVBORw0KGgo.... The browser decodes this and displays the image without making an HTTP request.
When Should You Use Base64 Images?
Base64 is ideal for:
- Small icons and logos (under 5-10KB)
- Images used only once (no caching benefit from a separate file)
- Email HTML where external images may be blocked
- Single-file HTML documents
- API responses where you need to include image data in JSON
When NOT to Use Base64
Base64 increases file size by approximately 33% because it uses 4 characters to represent every 3 bytes. For larger images this overhead is significant. Separate image files can also be cached by the browser, whereas inline Base64 cannot. For images over 10-20KB, always use a separate file.
Convert Images to Base64 Free
Our Image to Base64 Converter supports drag-and-drop encoding to Data URI, HTML img tag, CSS background-image or raw Base64. It also decodes Base64 strings back to viewable images — all in your browser with no server upload.
