Is my image uploaded anywhere?

No. The image is read locally with your browser's FileReader and encoded in memory — it is never uploaded, stored or seen by anyone.

Is the data URI an exact copy of my image?

Yes. FileReader encodes the original file bytes as base64 without re-compressing, so the embedded image is byte-for-byte identical to the file you selected.

Why is the data URI bigger than my file?

Base64 encoding adds roughly 33% to the size, so data URIs suit small icons and inline assets rather than large photos, where a normal file link is more efficient.

Image to Base64 Data URI

Turn an image into a base64 data URI without uploading it

A data URI lets you embed an image directly inside your HTML, CSS or Markdown instead of linking to a separate file — handy for tiny icons, email templates and self-contained pages. This tool reads your image and produces a data:image/...;base64,... string, with optional ready-to-paste HTML <img> or CSS background-image wrappers.

The image is read locally with your browser’s FileReader, so it is never uploaded, stored, or seen by anyone. Because base64 adds about a third to the size, data URIs are best for small assets rather than large photos.