Use this free website image size checker to find files that deserve a closer look. Check up to 50 unique image sources on a public page, then copy a prompt for an image table and alt text review. The tool does not compress or resize images.
Free. No login, AI API key, or WordPress plugin installation required.
Start with the actual file, then check how your theme delivers it. This checker provides evidence—not automatic compression or guaranteed speed improvements.
Inspect the image's displayed size at different screen widths in your browser. Compare it with the file's intrinsic dimensions and account for device pixel ratio. Select an appropriate WordPress-generated size instead of always using the full-size original.
Make a backup, then compare compressed versions at a few quality settings before replacing an image. Consider WebP or AVIF where your setup supports them, and check visual quality as well as file size. This tool measures PNG, JPEG, WebP and GIF; it does not measure AVIF or calculate potential savings.
Check responsive srcset and sizes so smaller screens receive suitable files. Lazy-load below-the-fold images, but do not blindly lazy-load the hero or likely LCP image. Use your browser's Network and performance tools to compare the delivered files and loading behavior before and after changes.
Write useful alt text for meaningful images and keep decorative alternatives empty where appropriate. Add relevant surrounding content. File size alone is not an SEO score, and good alt text depends on context.
Understand what the tool checks and what to review before making changes.
Our server fetches source HTML, selects at most 50 unique img sources, and downloads supported public image files within strict limits. Time and transfer limits can mean fewer images are measured. It reads dimensions from file headers without rendering images or executing page scripts. Explicit data-src/data-original lazy-load URLs take precedence over src placeholders; srcset is sampled only when no source URL is available. The file actually used by your browser may differ.
The prompt requests a table of sampled images with file sizes in MB, formats and alt text. Alt text is taken from the first occurrence of each source; a meaningful review of its accuracy also needs visual and page context.
No. This free checker helps you decide what to investigate; it does not install an image optimizer WordPress plugin, rewrite your media library, or change WP Rocket image optimization settings. Test any compression or delivery changes on your own site.
Public CDN URLs are allowed, but signed or unsupported query parameters, blocked requests, large files and timeouts may leave images unmeasured.
No stored images. No CSS rendering or JavaScript execution. No page-speed score, full-site crawl, visual-quality check, compression savings estimate or ranking guarantee. AI responses can be wrong or influenced by page text; review all recommendations before making changes.
Get in touch to discuss image optimization and performance improvements for your WordPress website.
