Compress an image to 85 KB

A banner of 1600 by 400 pixels is 640,000 pixels. At 85 KB that is about one bit per pixel, which is enough for a clean banner with gradients and text if the subject is not too detailed. A photograph of a crowd at the same size would look soft.

Headlines baked into a banner are sensitive to compression. JPEG leaves a faint haze around letters. If the file reaches 85 KB with haze visible, switch to WebP, or put the headline in real page text and keep the banner for the picture alone.

A wide banner gets cropped on a phone, so the part that matters should sit in the middle. Compress the version you will use on desktop, then make a narrower crop for phones that holds the main subject.

Banners often use a smooth colour gradient. Strong compression splits gradients into visible stripes. If you see stripes, raise the target to 120 KB or add a very slight texture to the gradient before you compress.

Pictures used as a page background are often scaled and moved as the reader scrolls. Compression artefacts then become more visible, because the eye follows the motion. Give a moving background a gentler target, around 120 KB, and keep 85 KB for static banners.

Start from the sharpest original you have. A banner built from a blurry source cannot be rescued by any setting. If you can choose, use a picture with a clear subject and a calm area where the headline will sit.

A good source saves more than any slider in the compressor.

Save the banner once as JPEG and once as WebP, then compare the sizes and the edges. For banners with smooth gradients WebP is usually smaller, while JPEG is supported almost everywhere. Choose whichever suits your site.

You can keep both results and serve them according to the browser.