PNG vs JPG: which format should you actually use?
Half the images on your computer are probably in the wrong format. Not broken, not corrupted, just quietly costing you four times the storage they should, or looking slightly worse than they could. The PNG vs JPG question sounds like trivia, but it decides how big your files are and how good they look, and the answer takes one paragraph to learn.
Here it is: JPG is for photographs, PNG is for everything with sharp edges. Screenshots, logos, charts, text, interface mockups: PNG. Anything that came out of a camera: JPG. That rule covers about 95% of real life. The interesting part is why, because once you see why, you’ll never mix them up again.
What JPG actually does
JPG was standardized in 1992, and its core trick is still remarkable. Instead of storing every pixel faithfully, it splits the image into small blocks and describes each block as a blend of patterns, keeping the patterns your eye notices and discarding the ones it doesn’t. Human vision is great at brightness and terrible at fine color detail, so JPG spends its bytes accordingly.
For a photograph, this is close to a free lunch. Photos are full of soft gradients, noise, and organic texture, exactly the material where you can throw away half the data and nobody can point to what’s missing. A 20 MB image straight off a sensor becomes a 3 MB JPG that looks identical on any screen you own.
The price appears when the image isn’t a photo. Feed JPG a screenshot with crisp black text, and those discarded patterns come back as a faint smudgy halo around every letter. The format is doing what it was built to do. You just handed it the wrong job.
What PNG actually does
PNG arrived in 1996, born out of a patent dispute over GIF, and it made the opposite bet: never throw anything away. It compresses the way a ZIP file does, finding repetition and encoding it efficiently, then handing you back every pixel exactly as it went in. Open and resave a PNG a thousand times and it will not degrade by a single bit.
That makes PNG unbeatable for synthetic images. A screenshot is mostly flat color and repeated shapes, which lossless compression eats for breakfast, so the file stays small and the text stays razor sharp. PNG also supports real transparency, which is why every logo you’ve ever dropped onto a slide was a PNG.
Point it at a photograph, though, and the logic inverts. A photo has almost no exact repetition, so PNG finds nothing to compress and the file balloons. The same picture that makes a 3 MB JPG routinely becomes a 15 MB PNG, and here’s the uncomfortable part: it doesn’t look any better. On a normal photo at normal viewing size, a well-made JPG and a PNG are visually indistinguishable. You’re paying five times the storage for a difference you cannot see.
The cheat sheet
| You have | Use | Why |
|---|---|---|
| A photo from any camera or phone | JPG | Huge savings, invisible losses |
| A screenshot with text or UI | PNG | Sharp edges stay sharp |
| A logo or icon that needs transparency | PNG | JPG has no transparency at all |
| A chart, diagram, or drawing | PNG | Flat colors compress losslessly |
| A photo you’ll edit again and again | PNG (or the original) | Each JPG resave loses a little more |
That last row deserves a sentence. JPG’s losses are invisible once, but they stack. Edit, save, edit, save, and after a dozen generations the smudge becomes real. So edit in a lossless format and export a JPG at the end, once.
So when do you convert?
The common direction is PNG to JPG, usually because a photo got trapped in a PNG somewhere along the way: an export from an editing app, a saved image from the web, a scan. Converting it back to JPG can cut its size by 70 to 80% with no visible change, which matters when you’re emailing it or watching your cloud storage fill up.
The reverse, JPG to PNG, is rarer and worth being honest about: it cannot restore detail the JPG already discarded. What it can do is stop any further loss, which is exactly what you want before opening a file for repeated editing.
One more thing worth knowing before you convert anything. Most conversion websites work by uploading your image to their server, and your screenshots and photos deserve better than a round trip through a stranger’s computer. This conversion is simple math, and your own device can do it. The converter below runs entirely in your browser: no upload, no signup, no size limits, and it works even with Wi-Fi switched off. Drop in a PNG and see for yourself.