Image Optimizer

Free Image Optimizer — Compress JPG, PNG & WebP in Browser

Images are almost always the largest assets on a webpage by file size. Unoptimized images slow down page loads, increase LCP scores, hurt Core Web Vitals, and waste bandwidth for mobile users on limited data plans. This free Image Optimizer compresses JPG, PNG, and WebP images directly in your browser with adjustable quality settings — no uploads, no servers, no data leaving your device.

Drop one or more images into the tool, adjust the quality slider, and download compressed versions instantly. The tool shows the original and compressed file sizes with the percentage reduction achieved, so you can dial in exactly the right quality-size balance for your needs.

Image optimization is a fundamental SEO task. Google's PageSpeed Insights consistently lists "Serve images in next-gen formats" and "Efficiently encode images" as the top two opportunities on most unoptimized sites. Fixing these alone can dramatically improve your Lighthouse score.

Image Optimization Best Practices

Use WebP format. WebP produces files 25–35% smaller than JPEG at equivalent visual quality. All modern browsers support WebP. Convert JPEG and PNG images to WebP for the web.

Resize before compressing. Do not upload a 4000px wide image and resize it in CSS. Serve images at their display size. A 800px wide image area needs an 800px image, not a 4000px one scaled down.

Use lazy loading. Add loading="lazy" to images below the fold. This defers loading until the user scrolls near them, dramatically improving initial page load speed.

Add descriptive alt text. Alt text helps Google understand image content, improves accessibility, and enables your images to rank in Google Image Search.

Use a CDN for images. Serving images from a Content Delivery Network (CDN) reduces latency for global visitors by delivering images from the server geographically closest to each user.

Related Tools

• Page Speed Checker – Audit full page performance and image issues.
• Image Crop Tool – Resize and crop images before optimization.
• Favicon Generator – Create favicons from any image.

Frequently Asked Questions