How image to base64 encoder works
Base64 encodes binary bytes into ASCII characters so an image can be embedded directly inside HTML or CSS as a data: URI instead of a separate file request. Every three bytes (24 bits) become four characters from a 64-symbol alphabet, with = padding when the byte count is not a multiple of three.
This tool reads your image with the browser FileReader API, converts the raw bytes to a base64 string, and wraps it in a data: URI of the form data:image/png;base64,<encoded>. You can paste that URI straight into an <img src> or a CSS url(). It also decodes data URIs back to bytes so you can inspect what is embedded.
Base64 data URIs increase size by about 33 percent and are best for small assets like icons, logos and placeholders. For large images a real file is more efficient. Everything happens locally — the image is never uploaded.