Three formats cover 95% of images on the modern web — but each was designed for a different job, and picking the wrong one either bloats your pages or wrecks your graphics. Here's the practical decision guide.
JPG: The Photograph Workhorse
JPG's lossy compression is engineered for the smooth gradients of real-world photos. It achieves small files by discarding detail the eye barely notices — but it has two hard limits: no transparency, and generation loss (quality degrades every time you re-save). Sharp-edged content like text and logos develops visible "ringing" artifacts.
Use JPG for: photos in emails and documents, camera exports, anywhere maximum compatibility matters.
PNG: Pixel-Perfect and Transparent
PNG is lossless: what you save is exactly what you get, forever. It supports full alpha transparency, which makes it the standard for logos, icons, screenshots and any graphic layered over other content. The cost is size — a photo saved as PNG is routinely 5–10× larger than the same photo as JPG.
Use PNG for: logos, screenshots, diagrams, images that need transparency, and any file you'll edit again.
WebP: The Web Performance Format
WebP does both jobs with modern compression: lossy WebP beats JPG by roughly 25–35% at equal visual quality, and lossless WebP beats PNG by around 25%. It supports transparency and even animation. Browser support is now universal; the remaining gaps are older desktop software and some upload forms that still refuse it.
Use WebP for: every image on a website you control. It is the single easiest page-speed win available.
Real-World Size Comparison
| Content | JPG (80%) | PNG | WebP (80%) |
|---|---|---|---|
| 2000px photo | ~450 KB | ~3.5 MB | ~300 KB |
| Logo with transparency | n/a | ~40 KB | ~28 KB |
| Full-page screenshot | ~380 KB (fuzzy text) | ~600 KB (crisp) | ~350 KB (crisp) |
Rules of Thumb
- Photo for the web? WebP, fall back to JPG if the destination rejects it.
- Needs transparency? PNG (or WebP for the web) — never JPG.
- Will be edited repeatedly? PNG, to avoid compounding JPG loss.
- Uploading to a picky old system? JPG — nothing is more universally accepted.
Converting Between Formats (Free, In Your Browser)
Conversion takes seconds with browser-based tools — no upload, no watermark: JPG→PNG, PNG→JPG, PNG→WebP, WebP→JPG, or shrink any of them with the Image Compressor's smart mode, which automatically picks the smallest format for each image.
The format wars have a happy ending: use WebP where you control the platform, JPG where you don't, and PNG whenever pixels must be perfect.