Image to Base64

A data URI embeds the image directly into your HTML or CSS as an encoded text string, using the format data:image/png;base64,iVBORw0KGgo.... This eliminates external image requests, which helps with performance in single-file deployments, email attachments, and cached pages that must work offline.

Base64 encoding increases file size by approximately 33% compared to the original binary. A 30KB PNG becomes about 40KB when encoded. This overhead can outweigh the benefits for larger images. Best practice is to reserve Base64 embedding for small images under 5-10KB such as icons, buttons, and UI elements.

Yes, embedding images as data URIs is an excellent strategy for email. Many email clients block external image requests for privacy reasons, but embedded images display regardless. Email newsletters and marketing campaigns frequently use this technique for logos, product images, and social icons.

No. All processing happens locally in your browser. Images you upload are converted to Base64 entirely on your device using the FileReader API. Your original images never leave your browser.

Loading images from URLs requires the remote server to allow cross-origin requests through CORS headers. Many image hosting services and CDNs support this, but some websites block external requests. If loading fails, try downloading the image first and uploading it directly instead.

When you embed images as data URIs, the HTML file containing them becomes the cache target rather than separate image files. If the HTML gets revalidated, the embedded images come along. For frequently cached pages, this can improve perceived performance by reducing total HTTP requests, though the initial page size increases.