Image to Base64

Base64 is a way of encoding binary data (like images) as plain text using only 64 safe ASCII characters. Since images are binary files, they can’t be directly embedded in text-based formats like HTML, CSS or JSON. Base64 converts the binary data into a text string that can be included anywhere text is accepted. The tradeoff is that Base64 strings are about 33% larger than the original binary file.

A Data URI combines the image’s MIME type and its Base64-encoded content into a single string that browsers can use as an image source. It looks like: data:image/png;base64,iVBORw0KGgo.... You can use this directly as the src attribute of an <img> tag or as a CSS url() value.

Base64 encoding increases file size by approximately 33% because it represents every 3 bytes of binary data as 4 ASCII characters. This is an inherent property of the encoding scheme. For web use, this means Base64 embedding is best suited for small images like icons, logos, and small decorative elements — not large photographs.

Base64 is best for: small images under ~5KB (icons, logos, small patterns) where eliminating an HTTP request saves more than the size increase costs; HTML emails where external image loading is often blocked; single-file HTML documents that need to be self-contained; and API payloads that need to transmit images as text. Avoid Base64 for large photos — the size overhead and loss of browser caching make it inefficient.

No — the conversion happens entirely in your browser using the FileReader API. Your image is read locally and converted to Base64 on your device. Nothing is sent to our servers. This makes the tool instant, private, and usable even without an internet connection once the page has loaded.