Image to Base64 Converter
Convert images to Base64 encoded strings for HTML, CSS, and APIs
Upload Image
Drop an image here or click to browse
PNG, JPG, GIF, SVG, WebP, AVIF
Output
Upload an image to see the Base64 output
Frequently asked questions
What is a Base64 data URI?
A data URI is a string that embeds file content directly into HTML or CSS, formatted as data:[mime-type];base64,[encoded-data]. It lets you use images without separate HTTP requests, which can speed up small-image-heavy pages.
Is my image uploaded to a server?
No. This tool uses the browser's built-in FileReader API entirely client-side. Your image never leaves your device.
Why is the Base64 string 33% larger than the original?
Base64 encoding converts 3 bytes of binary data into 4 ASCII characters, adding roughly 33% overhead. This is a trade-off for text compatibility when you need to embed binary data in HTML, CSS, or JSON.
When should I use Base64 images?
Best for small images (icons, logos under ~5 KB) that are critical for first render, or when building email HTML where external image links may be blocked. For large images, a URL reference is more efficient.