Guide•~5 min read

Image to CSS Converter: How to Turn Any Picture into Pure CSS

Image2CSS converts images into CSS box-shadow code that renders in any browser without a single image file. Here's exactly how to use it — from upload to download.

Step 1: Upload Your Image

Go to the Image2CSS homepage and drag-and-drop any image onto the upload area, or click to browse. Supported formats include JPEG, PNG, WebP, GIF, BMP, AVIF, and SVG — essentially anything your browser can display. Maximum file size is 20 MB.

Your image stays on your device. Nothing is uploaded to any server — the entire conversion runs in your browser using the HTML5 Canvas API. This is a core design principle of Image2CSS, not just a feature.

Step 2: Configure Resolution & Style

Once your image loads, you'll see the conversion preview immediately. Use the controls to adjust:

Resolution: Controls the output width in pixels (16–400). Lower = smaller file, faster render. Higher = more detail, larger CSS.
Pixel Size: The visual size of each CSS "pixel" in the output. Larger values create a mosaic/pixel-art look.
Colour Mode: Choose full colour, grayscale, or black-and-white threshold for high-contrast art.

The preview updates in real time as you tweak settings. The file size comparison shows you exactly how the CSS output compares to your original image.

Step 3: Preview the CSS Art

The canvas renders your image as CSS box-shadow art live. Each coloured square you see is a single box-shadow value — there are no image files involved. Toggle between your original photo and the CSS version to compare quality.

For most use cases, 96–128px resolution hits the sweet spot between recognisable detail and manageable file size. For logos and icons, even 32–64px produces clean results.

Step 4: Download or Copy

When you're happy with the result, download a ZIP containing a standalone index.html and style.css. Open the HTML in any browser and the image renders purely through CSS. You can also copy just the CSS to your clipboard for pasting into existing projects.

When to Use an Image to CSS Converter

CSS box-shadow images are ideal for:

Lightweight icons that avoid HTTP requests

Privacy-sensitive contexts where image loading is restricted

Offline-capable pages and PWAs

Creative CSS art and portfolio pieces

For full-size responsive photographs, a standard <img> tag with srcset remains the better choice. CSS art excels as a lightweight, privacy-first, dependency-free image format for small-to-medium visuals.

Frequently Asked Questions

What is an image to CSS converter?

An image to CSS converter transforms raster images (JPEG, PNG, WebP, etc.) into CSS code using the box-shadow property. Each pixel becomes a box-shadow entry, recreating the image in pure CSS with no image file dependency.

Is Image2CSS really free?

Yes. Image2CSS is completely free with no limits, no accounts, no watermarks, and no restrictions. It runs entirely in your browser — there is no server-side processing or data collection.

What resolution should I use?

For small icons and logos, 32–64px is ideal. For illustrations, 96–128px works well. For photos where you want recognisable detail, 128–200px balances quality and file size. Going above 300px produces large CSS files and heavy rendering.