Image Compressor

80% is the usual sweet spot for photographs - typically a 60 to 80% size reduction with no visible difference. Below 60% compression artefacts start showing on gradients and skin tones.

No. It re-encodes as JPEG, which is lossy by definition. That is what makes the saving large. For lossless compression you want a PNG optimiser instead.

PNGs with few colours are already efficiently compressed, and re-encoding a screenshot as JPEG can grow it. For flat-colour images, convert to WebP instead.

Under 200KB for a hero, under 100KB for anything else. Google flags images over roughly 500KB as a Core Web Vitals problem, and they are usually the cause of a slow LCP.

Under 200KB for a hero and under 100KB for everything else. Google's Lighthouse flags images that could save more than 4KB, which in practice means most unoptimised photos.

Lossy discards detail the eye is unlikely to notice and cannot be undone. Lossless rearranges the data so it reconstructs exactly, and saves far less. JPEG and WebP are lossy; PNG is lossless.

Screenshots are flat colour and sharp text, which JPEG handles badly - it produces ringing around the edges. Keep screenshots as PNG or lossless WebP.

Indirectly and reliably. Images are the largest asset on most pages, so they usually determine Largest Contentful Paint, which is a ranking signal.