What the Encoder Produces
The browser reads the selected image as a Data URL in the form data:image/type;base64,.... The prefix identifies the MIME type; the text after the comma is the Base64 representation of the original file bytes.
Choose Data URL when the destination expects a self-contained value for HTML, CSS, or a small prototype. Choose Raw when an API field already carries the MIME type separately and needs only the Base64 payload.
Size and Format Boundaries
Base64 does not compress an image or change its format. A JPEG stays JPEG bytes and a PNG stays PNG bytes; only the byte representation is converted to text. Base64 expands binary data to roughly four characters for every three input bytes, before any surrounding JSON or markup overhead.
Large images are therefore usually better served as normal files or object-storage URLs. Data URLs are most useful for small assets, test fixtures, or systems that specifically require embedded data.
Local Processing and Reverse Conversion
The selected file is read with the browser File API and is not uploaded to this website. The browser must identify it as an image MIME type before the tool accepts it.
To verify an encoded result, paste it into Base64 to Image. For text rather than image files, use the general Base64 encoder/decoder.