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The Problems That Come with Large Image Files

A single photo from a modern smartphone can weigh 4–6MB. Great image quality is obviously an advantage. But what happens when you upload that original file to a blog, attach it to an email, or use it as a product photo in an online store?

Problems Caused by Large Image Files

How Much Should You Compress?

It depends on the use case. For general web images at 1200px wide, JPEG at 80% quality typically lands in the 100–300KB range. Thumbnails can be 20–50KB. Print images, on the other hand, should prioritize quality over compression.

The key question is "where will it be used?" A fullscreen background image on a retina display can accommodate 200–400KB. But using a 2MB image for a list-page thumbnail is clear waste.

Which Format Should You Use?

Format choice alone can dramatically change file size. Compared to JPEG at equivalent quality, WebP is roughly 25–35% smaller, and AVIF is about 40–50% smaller. For photos that don't need transparency, WebP is currently the most practical choice. It's supported in Chrome, Firefox, Safari, and Edge.

For logos, icons, or images with simple colors that need a transparent background, use PNG — it also preserves text sharpness better. AVIF is the most efficient option but requires Chrome 94+, Firefox 93+, or Safari 16+. If you need to support older browsers, use WebP.

Things to Keep in Mind When Compressing

JPEG and WebP lose quality every time you save them. Re-opening and re-saving an already-compressed file degrades it further. Always keep your originals separate and use compressed copies for distribution. PNG is a lossless format — saving it repeatedly doesn't change the pixels.