How to use the Image to Base64 Converter
- 1. Choose an imagePNG, JPG, GIF, WebP, SVG or ICO, up to 10 MB.
- 2. ConvertThe file is read in your browser and encoded to Base64.
- 3. Copy or saveCopy the data URL, or download it as a text file.
When Base64 images help, and when they hurt
A Base64 data URL puts an image inside your HTML, CSS or JSON, so it loads without a separate request. That is handy for tiny icons, email signatures, a logo inside a single-file HTML report, or sending an image through a JSON API.
The cost is size: Base64 is about 33% bigger than the original file, and a Base64 image cannot be cached on its own, so it is downloaded again with every page that includes it. For photos and anything over about 20 KB, a normal image file is usually faster.
Worked example
Base64 turns every 3 bytes into 4 characters, so the length is 4 × ⌈bytes ÷ 3⌉. A 3,000-byte PNG icon becomes exactly 4,000 characters, which the tool reports as 33% bigger. The result is shown three ways:
- Data URL:
data:image/png;base64,iVBORw0KGgo…, ready to paste anywhere a URL goes, such as an img src, a CSS url() or a JSON field. - HTML:
<img src="data:image/png;base64,…" alt="">. Remember to write real alt text. - CSS:
background-image: url("data:image/png;base64,…");
The image type in the prefix comes from the file's own header bytes, so a PNG renamed to .jpg still gets the right image/png prefix. If you only need the raw Base64 without the prefix, for example for an API that expects plain Base64, copy that version instead.
Frequently asked questions
Is my image uploaded?
No. It is read and encoded on your device.
Can I convert SVG?
Yes. For SVG, plain text in a data URL (URL-encoded) is often smaller than Base64, but Base64 always works.
Is there a size limit?
10 MB. Base64 is meant for small images, and huge strings slow down editors and pages.
Is the image to base64 converter free?
Yes, it is free. Converting your first image asks for your name and WhatsApp number once, and after that the image to base64 converter and every other Uncodemy tool open without the form.