1200x800 pixels (3:2 ratio) is an ideal size for blog featured images and general web content. It provides excellent detail at common content widths while remaining performant for page load times.
At this dimension, JPEG images are typically 80-150KB at 80% quality, which falls within recommended performance budgets. The 3:2 ratio works well for content areas and looks balanced above blog post titles.
With ImgTools, upload your image, crop to 3:2 if needed, and resize to 1200x800. For retina displays, some developers prefer 2400x1600 as the source with CSS constraints at 1200x800.
All processing happens locally in your browser.