Image to Base64 Converter Online

Image Data URIs: Embedding Images Without Files

A data URI is a way to embed a file's contents directly into a URL. Instead of pointing to an external file (src="logo.png"), it inlines the file as Base64: src="data:image/png;base64,iVBORw0KGgo...". The browser decodes and renders it with no extra HTTP request.

📦 When to Use Image Data URIs

• Email HTML: many email clients block external image URLs. Inlining images as data URIs guarantees they display — used in transactional emails, signatures, and inline attachments.
• CSS background icons: tiny SVG icons and UI sprites can be embedded directly in stylesheets, removing the need for image server hosting.
• Offline apps / PWAs: data URIs work without a network connection — useful for splash screens, icons, and assets in service workers.
• API payloads: if your API needs to send an image inside a JSON body, Base64 is the standard encoding (though multipart/form-data is preferred for large files).
• Canvas export: canvas.toDataURL() returns a PNG as a Base64 data URI — useful for client-side screenshot or image generation tools.

⚖️ Tradeoffs

📐 Size Rule of Thumb

Data URIs are a good choice for images under ~5 KB (icons, avatars, small decorative elements). For anything larger, serve the image as a separate file — CDNs, HTTP/2 multiplexing, and browser caching will outperform inlining. For SVGs specifically, inline the raw SVG markup rather than Base64-encoding it: it's smaller and remains accessible to CSS and JavaScript.

Your images are read locally by the FileReader API and never uploaded anywhere.