Image to Base64 Converter — Encode Images for HTML & CSS
Convert images to Base64 encoded strings
Convert any image to Base64 string for embedding in HTML, CSS, or JavaScript. Supports JPG, PNG, WebP, SVG.
About Image to Base64
Base64 is a binary-to-text encoding scheme that converts binary data into an ASCII string using 64 printable characters. When applied to images, it produces a data URI that browsers can interpret directly without making a separate HTTP request.
Embedding images as Base64 data URIs is a useful optimisation for very small images such as loading spinners, favicons, small icons, and decorative patterns. By inlining them in CSS or HTML, you eliminate the latency of an additional HTTP round-trip. This technique is especially valuable for above-the-fold content where reducing render-blocking requests improves First Contentful Paint.
Common use cases include embedding small logo or icon images in email HTML (where external image URLs are often blocked by email clients), inlining spinner animations in CSS, and creating self-contained HTML files that include all their assets.
Important trade-off: Base64 encoding inflates the data size by approximately 33% and prevents browser caching of the individual image. For images larger than 5 KB, serving them as separate files is almost always more efficient. The generated Base64 string is ready to paste into img src attributes, CSS background-image values, or any JSON payload. All encoding runs in your browser — no data is sent externally.
Frequently Asked Questions
What is Base64 encoding used for?
Base64 encodes binary data (like an image) as a text string, allowing it to be embedded directly in HTML, CSS, or JavaScript without requiring a separate HTTP request. It is commonly used for small icons, logos, and inline CSS background images.
Does Base64 encoding increase file size?
Yes. Base64 encoding increases the data size by approximately 33%. It is recommended only for small images (under 5 KB) where eliminating an HTTP request outweighs the size overhead.
How do I use a Base64 image in HTML?
Use the data URI as the src attribute: <img src="data:image/png;base64,YOUR_BASE64_STRING" />. For CSS, use it as a background: background-image: url("data:image/png;base64,YOUR_BASE64_STRING");
What image formats can be converted to Base64?
Any image format the browser can read — including JPEG, PNG, WebP, GIF, and SVG — can be converted to a Base64 data URI.