Drop the image into a browser-based Base64 converter and it produces a data URI you can paste straight into an img tag or a CSS url() value. The encoding happens on your device, so the image is never uploaded, and the tool is free with no account.
A Base64 data URI embeds the image bytes directly inside your HTML or CSS as text, so the picture loads with the document instead of as a separate network request. That is handy for small icons, email signatures, single-file HTML pages and quick prototypes where you do not want to host an image file at all.
Base64 encodes three bytes of image into four characters of text, so the embedded version is roughly a third larger than the original file, and it cannot be cached separately from the page. That makes data URIs a good fit for small images and a poor one for large photos. Since the encoding is pure text manipulation, the tool does it entirely in your browser and nothing is sent anywhere.
No. The file is read and encoded locally in your browser.
Base64 represents binary data as text with about 33 percent overhead, so the string is roughly a third larger than the original image.
For small images like icons and logos embedded in HTML, CSS or emails. Large photos are better served as normal image files.