Optimize Images for Websites

The tool applies three web-specific optimisations: it resizes your image so the longest side does not exceed 1920 pixels (the maximum width of a full-screen desktop display), converts the output to WebP format at quality 75 using the highest-effort compression method (method 6), and adds a one-year Cache-Control header to the response. WebP at quality 75 typically produces files 25–35% smaller than equivalent JPEG quality at visually indistinguishable quality for web viewing.

WebP is currently the best format for web images. At equivalent visual quality, WebP produces files 25–35% smaller than JPEG for photographs and up to 50% smaller for graphics. All modern browsers — Chrome, Firefox, Safari, Edge — support WebP. Google also considers WebP as a best practice in PageSpeed Insights and rewards it with an 'Efficient format' check. The tool converts to WebP automatically so you immediately get the web performance benefit without any configuration.

1920 pixels is the width of a full-screen 1080p desktop display — the most common desktop resolution in use. Images wider than 1920px contain more pixels than any standard screen can display, meaning the extra data is downloaded but never rendered. Resizing to 1920px longest side eliminates this wasted bandwidth without any visible quality loss at any standard display size.

WebP quality 75 uses the maximum compression effort (method 6) at a quality level that is visually indistinguishable from higher settings at normal web viewing distances and screen sizes. Most users cannot distinguish quality 75 WebP from quality 90 JPEG on a web page. The tool uses method 6, which takes longer to compress but achieves the smallest possible file size at quality 75 — prioritising the best size/quality ratio for web delivery.

Yes — specifically for the 'Serve images in next-gen formats' and 'Properly size images' recommendations. Converting to WebP directly addresses the 'next-gen formats' recommendation, which is one of the highest-impact PageSpeed Insights opportunities. Resizing to 1920px addresses 'properly size images' for most full-width web images. Together these changes can contribute significant improvements to the Performance score in Lighthouse and PageSpeed Insights.

WebP compression supports methods 0 through 6, where method 6 applies the most thorough compression algorithm — searching more extensively for the optimal way to represent the image data. This results in the smallest possible WebP file at a given quality level but takes longer to process. For web images that are compressed once and served many times, method 6 is always the right choice: the extra processing time is negligible compared to the cumulative bandwidth savings across all page loads.

The tool's response includes a Cache-Control: public, max-age=31536000 header, which tells browsers to cache the image for one year. When a returning visitor loads a page, the browser serves the image from local cache rather than downloading it again — making subsequent page loads essentially instant for that image. This is a best practice for static web assets and contributes to improved repeat-visit performance scores.

Yes — completely free with no usage limits and no watermark on the output. Optimise as many images as you need for any website project at no cost.