Almost every oversized image on the web is the result of one of three mistakes: the wrong format, an unnecessarily high quality setting, or — most often — dimensions far larger than anything the screen will display. Get those three levers right and a 4 MB photo becomes a 200 KB one that looks identical.
This hub teaches the decision behind each lever, then links the tools that apply it. Because everything runs locally, you can optimise a passport scan or a private photo without it ever touching someone else's server.
Pick the format before you touch quality
Format is the lever with the biggest payoff and the most confusion. Photographs want JPEG or WebP; screenshots, logos and anything with hard edges want PNG or WebP; transparency rules JPEG out entirely. WebP and AVIF win on raw efficiency. The full decision tree — with the trade-offs spelled out — is in the 2026 image-format decision guide, and you switch formats with Convert Image.
Then size for the screen, not the sensor
A modern phone shoots 12–48 megapixels. A full-width web image is rarely more than 2 megapixels' worth of visible detail. Serving the original is the single biggest waste on most pages, and resizing fixes it faster than any quality slider — usually by an order of magnitude. Resize images for the web covers the target sizes, and Resize Image and Compress Image apply them. To assemble a private, no-upload workflow from drop to download, follow the browser-only image pipeline.
Guides in this hub
Tools to put it into practice
Shrink JPEG, PNG, and WebP without visible quality loss.
Convert between PNG, JPG, and WebP in seconds.
Change dimensions with high-quality resampling.
Crop with aspect-ratio presets — square, 16:9, portrait, freeform.
Strip camera, GPS and other metadata from photos before sharing.
Frequently asked questions
Should I compress or resize first?
Resize first, then compress. Capping dimensions to what you actually display removes pixels the screen will never show — a far bigger win than tuning quality on an oversized image.
Is WebP safe to use everywhere?
For the web, yes — every major browser has supported WebP since 2020, and it's 25–35% smaller than JPEG at the same perceived quality. The one exception is systems that still demand JPG, like some forms and email clients.
Will converting strip my photo's GPS location?
Not always — conversion can carry EXIF metadata over. If you're sharing a photo, run it through Remove EXIF to strip GPS, device and timestamp data explicitly.