Image Optimization Guides
Practical guides to compressing, resizing and converting images for the web, with quality checks and format recommendations you can apply to real files.
Updated
Good image optimization is not about chasing the smallest possible file. It is about delivering an image that is appropriately sized, visually suitable and encoded in a format that works for its audience. These guides turn that decision into a repeatable workflow.
Start with the task you need to complete. You can learn how to compress or resize a set of images, choose between common formats, understand quality controls, or compare WebP and AVIF using criteria that matter in production.
Start with these principles
Resize an image to realistic display dimensions before trying to solve everything with compression.
Choose a format for the image and delivery context rather than using one format for every asset.
Judge quality at the size and pixel density visitors will actually see.
Keep editable source files separately from optimized delivery copies.
Test representative images before applying one setting to a whole batch.
Choose the job you need to do
Reduce delivery weight
Work through dimensions, format, quality and final visual inspection in the right order.
Protect transparency
Optimize product cut-outs and soft alpha edges without introducing unwanted backgrounds or halos.
Keep screenshots crisp
Treat labels, rules and flat fills as details that need deliberate lossless or conservative encoding.
A reliable optimization workflow
Define the image’s job
Identify where the image will appear, its largest rendered size, whether it needs transparency and how closely people will inspect it. A hero photograph and a small interface icon need different decisions.
Remove unnecessary dimensions
Do not routinely deliver camera-sized files into modest content slots. Create dimensions appropriate for the layout, retaining enough pixels for the highest density you intend to support.
Test a suitable format
WebP is a practical first test for many assets. AVIF can be valuable for large photographic images. JPEG remains useful for traditional compatibility, while PNG protects sharp detail and transparency where file size is secondary.
Review the actual output
Compare file weight and visible quality. Look closely at faces, gradients, text, fine edges and transparency. If a setting damages important detail, increase quality or test another format.
Looking for format specifications?
Use the format library for focused WebP, AVIF, JPEG and PNG references.