Image to Base64 Converter
Convert an image into a Base64 string or data URI for HTML, CSS, JSON and API testing without uploading the file.
Up to 20 MiB and 40 million pixels per image. Contact sheets accept 2–50 images, up to 100 MiB total. Icon outputs fit the complete image inside a square with transparent padding.
Why this tool exists
Base64 is best for small assets because it increases payload size.
- ✓ data URI
- ✓ raw Base64
- ✓ copy
- ✓ download text
Useful for
- • CSS backgrounds
- • HTML prototypes
- • API fixtures
Turn a small image into Base64 or a data URI
Base64 embeds binary image bytes as text. It is useful for small HTML, CSS, JSON fixtures and API experiments, but the encoded representation is larger than the original bytes.
Use Base64 where embedding is actually useful
Small icons, test fixtures and self-contained prototypes are common use cases. Large photographs are usually better kept as normal files because Base64 increases payload size and makes source code harder to manage.
Choose data URI versus raw Base64
A data URI includes the MIME type and the Base64 payload so it can be placed directly in HTML or CSS. Raw Base64 is useful when an API or application expects only the encoded string.
Frequently asked questions
What is an image Base64 string?
It is a text representation of the image bytes using Base64 encoding. A data URI adds the image MIME type and the required prefix.
Does Base64 reduce image size?
No. Base64 generally increases the size of the binary payload. Its advantage is that the image can travel inside text-based data.
Should I Base64 encode a large photo?
Usually not. For large assets, a normal image file or URL is generally more practical.
Can I use an image data URI in CSS?
Yes. A correctly formed data URI can be used as a CSS image value when the asset is small enough to make that approach practical.