Website Image Size Checker

Enter any URL to instantly scan every image on the page. See natural dimensions, rendered sizes, image type, and visibility — all in one report.

What This Tool Checks

HTML Images

Every <img> tag on the page with src, alt text, and full dimension data.

CSS Background Images

Background images set via CSS that browsers don't expose in standard inspectors.

Natural vs Rendered

Compare the original file dimensions with how the image actually displays on screen.

JavaScript Rendering

Full browser rendering catches images loaded by React, Vue, and other frameworks.

Why Check Image Sizes on a Website?

  • Performance: Oversized images are the #1 cause of slow page loads and poor Core Web Vitals scores.
  • SEO: Google uses Largest Contentful Paint as a ranking signal — slow images hurt rankings.
  • Bandwidth: Serving a 4000px image in a 400px container wastes 90%+ of the data transferred.
  • Responsive design: Verify that images scale correctly across different viewport sizes.

How It Works

  1. Enter any public URL above
  2. We launch a headless browser to fully render the page, including JavaScript
  3. Every image is analyzed — both HTML and CSS background images
  4. Results show natural dimensions, rendered size, visibility, and image type

Frequently Asked Questions

Is this tool free?

Yes, completely free with no account required.

Does it work with JavaScript-heavy sites?

Yes. We use a full headless browser (Puppeteer) that renders JavaScript, so React, Vue, Angular, and other framework-based sites work correctly.

What's the difference between natural and rendered dimensions?

Natural dimensions are the original pixel size of the image file. Rendered dimensions are how large it actually appears on the page. If natural is much larger than rendered, the image is oversized and wasting bandwidth.

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