Website Image Compression Savings Calculator

Why images are your biggest bandwidth bill

Most websites are images wearing a little text on top. A single unoptimized phone photo uploaded to a blog can weigh 3-4 MB, and that full weight travels across the internet every time someone opens the page. Ten images at 3 MB each means 30 MB per visit; multiply by a thousand daily visitors and you are pushing almost a terabyte of image data a month — often the largest line on your hosting bill.

How much compression really saves

Modern formats change the math. Exporting a JPEG as WebP typically shrinks it 25-35% with no visible change; AVIF can cut 50% or more. Simple "light" compression (around 25%) is safe for every image. A standard pass (about 60%) is the sweet spot for most sites — visually identical at normal zoom. Aggressive compression (about 85%) is for thumbnails and backgrounds where absolute sharpness does not matter.

Worked example

Say your blog publishes 200 images a month, averaging 850 KB each, and each image is viewed 1,000 times a month. Standard 60% compression shrinks each image to 340 KB, saving 510 KB per image. That is 99.6 MB of storage saved every month — 1.17 GB over a year. The bandwidth saving is much bigger: 97.3 GB of transfer per month, which at a typical $0.08 per GB host rate saves about $7.78 every month.

Practical tips to keep images light

Resize images to the largest size they will actually be displayed at — a 4,000 px photo shown at 800 px wastes 90% of its bytes. Serve WebP or AVIF with a JPEG fallback for old browsers. Enable lazy loading so below-the-fold images only download when scrolled to. Batch-compress your existing media library once, then compress every new upload before it goes live.