Why image size matters
Every image increases the amount of data a browser must transfer, decode, and draw. On mobile networks, oversized pictures can significantly delay the moment when a page feels ready. But compression is not simply a race for the smallest possible number of bytes. A hero photo with obvious compression artifacts can look worse than a slightly larger, clean export. The useful goal is an efficient file at the dimensions and quality the page actually needs.
Start with dimensions
Check how large the picture will appear in your layout. A 5000-pixel photo rarely needs its full resolution to fill a 600-pixel article column. Exporting at approximately the display size, sometimes with extra pixels for high-density screens, reduces the work of encoding and downloading the file. Resize before adjusting the final compression settings so you judge the actual output.
Choose a sensible quality level
For natural photos, a JPEG or WebP quality setting around 75–85 is often a useful starting point. This is not a universal recommendation: gradients, thin text, skin texture and intricate details may require different settings. Compare the processed image at its actual viewing size rather than relying only on a percentage. WebP and AVIF can offer more efficient encoding, but browser support and workflow compatibility matter.
Compare and keep your original
Look at the edges of objects, smooth skies, backgrounds and small lettering. If the processed file becomes larger, do not automatically replace the original. PNG recompression in browsers in particular may be less efficient than purpose-built optimizers. Save the source file so future edits can begin from the highest-quality version, then test your actual web page with the exported image.
Useful tools
Start with the CompIMG Compress Images tool, then try Resize Images and Convert Image Formats. You can process a small batch together and download an archive when you are satisfied with the results.