Utilities
Image Base64
Convert images to Base64 data URLs for CSS and HTML embeds.
About Base64 Image
Turn an image into a Base64 data URL in your browser and copy it as the bare Base64 string, a CSS background, an HTML img tag or the full data URL. Inlining saves an HTTP request for tiny icons, and the tool warns you when the result is over 100 KB.
Frequently asked questions
When is a base64 image bigger than a regular file?
Always: base64 adds roughly 33 percent overhead. Use it only for small images where saving the HTTP round-trip matters more than the size cost.
Do email clients support data URIs?
Not all of them. In the tests on caniemail.com, Gmail didn't show data URI images on any platform, and Outlook for Windows only from Outlook 2019 on and without GIFs, while Apple Mail, Yahoo and Outlook.com did. For email, attach the image with a CID reference or link to a hosted copy instead.