webutilkit

Image to Base64 Data URL

Convert an image into a base64 data URL for inlining in CSS or HTML. Never uploaded.

Files are processed in your browser and never uploaded.

Data URL
How it works


The browser reads your file with the FileReader API and returns it as a data
URL: the MIME type followed by the file’s bytes in base64. The file never
leaves your device, so you can safely convert images you would not want to
upload anywhere.


When to use it


Inlining a small icon into CSS to avoid an extra request, embedding a logo in
an HTML email, or pasting an image into a JSON payload or config file that
only accepts text.


Limitations


Base64 adds roughly 33 percent to the file size, so this is a poor trade for
anything but small images. Inlined images cannot be cached separately by the
browser. This tool accepts files up to 5MB.
Frequently asked questions
Is my image uploaded to a server?
No. Files are processed in your browser and never uploaded. The conversion uses the browser FileReader API entirely on your device.
Why is the data URL larger than my image file?
Base64 encoding represents binary data using 64 text characters, which costs roughly 33 percent more bytes than the original. Inline images trade size for saving an HTTP request.