PNG vs JPG vs WebP: Which Image Format Should You Actually Use?
I once watched a colleague upload a 4 MB PNG screenshot to a blog post. Converted to JPG it was 180 KB and looked identical. That single format choice was costing every visitor a 20x slower load — multiplied across thousands of readers. Format choice is the highest-leverage image optimization there is, and it takes ten seconds.
Here's the honest comparison of the three formats that matter, the situations where each wins, and the simple decision rule I use so I never have to think about it twice.
JPG: the photograph workhorse
JPG uses lossy compression tuned for photographs: it throws away detail your eyes won't miss in exchange for tiny files. A 12 MP phone photo might be 4 MB as PNG but 400 KB as high-quality JPG with no visible difference. That's why every camera and every social platform defaults to JPG for photos.
JPG's weaknesses: no transparency, and quality degrades every time you re-save (generation loss). Never use JPG for images with sharp text or logos — the compression smudges edges into visible artifacts. And never edit-and-resave the same JPG repeatedly; keep a lossless master.
PNG: the crisp graphics choice
PNG is lossless: every pixel is preserved exactly. That makes it perfect for screenshots, logos, diagrams, and anything with text or sharp edges — plus it's the classic choice when you need transparency. The price is file size: photographic content in PNG is enormous because lossless can't exploit how human vision works.
Rule of thumb: if the image has large flat areas of color, text, or needs transparency, PNG. If it's a photo, almost never PNG.
WebP: the modern best-of-both
WebP does lossy compression like JPG and lossless like PNG, plus transparency and animation — and it beats both at their own game. A WebP is typically 25–35% smaller than the equivalent JPG and dramatically smaller than PNG. Browser support is now universal, so the old 'but Safari...' objection is dead.
- Photos for the web → WebP (lossy, quality ~80).
- Screenshots with text → WebP lossless or PNG.
- Need transparency → WebP or PNG.
- Archiving originals → keep the source format; convert copies for publishing.
My personal default is now WebP for everything published online, falling back to JPG only when some ancient system demands it. Converting takes seconds with our free Image Format Converter — and it all happens in your browser, so your images are never uploaded. Once the format is right, I usually shrink the file further with our Image Compressor — same story: local, private, no upload. I went deeper on the quality side of that step in my guide to compressing images without losing quality.
What about AVIF and GIF?
AVIF is the next step beyond WebP: it can be 20–30% smaller again at the same quality, with excellent color depth. The catch is encoding speed and compatibility — some older tools and social platforms still do not handle AVIF well, so I treat it as a publishing choice for modern websites, not a universal default. If your audience is mostly on current browsers, AVIF is worth testing; if you need guaranteed compatibility, WebP is still the safer bet.
GIF survives for one reason: simple animation. For a short looping clip with flat colors, GIF is universally supported, but it is limited to 256 colors and the files are huge compared with modern video. For anything photographic or longer than a few seconds, a short muted video file will look better at a fraction of the size. Use GIF only when you specifically need a self-playing image that works everywhere without a video player.
The decision rule stays the same regardless of format: photos go to a lossy format (JPG, WebP, or AVIF), graphics with text go to a lossless one (PNG or WebP lossless), and transparency is available in PNG, WebP, and AVIF — never JPG. Convert a copy, not your original, with our Image Format Converter, compare the file sizes side by side, and then shrink the result with our Image Compressor before publishing.