JPEG Beats PNG for Screenshots | Generated by AI
Two things at play:
Resolution vs compression tradeoff. The PNG was resized to 1000px — you permanently lost pixel data. The JPG kept the full original resolution but applied lossy compression at quality 50. More pixels + lossy > fewer pixels + lossless, visually.
PNG is lossless but wasteful for screenshots. A screenshot has gradients, anti-aliased text, and subtle color variations. PNG encodes every pixel exactly, which costs a lot of bits for that kind of content. JPG’s DCT (discrete cosine transform) compresses 8×8 blocks by discarding high-frequency detail humans barely notice — so it packs far more visual information per kilobyte.
The math roughly:
- PNG at 1000px, lossless: 451KB for ~1M pixels
- JPG at full res (~2400px?), quality 50: 463KB for ~5.7M pixels
The JPG stores ~5x more pixels in roughly the same space. Even with lossy artifacts, 5.7M pixels at quality 50 beats 1M pixels at lossless quality every time for perceptual sharpness.
For screenshots specifically, JPG quality 50-70 is the sweet spot — text stays readable, UI elements stay sharp, and the DCT compression handles flat color regions very efficiently. PNG’s lossless guarantee only wins when you need pixel-perfect accuracy (e.g., icons, pixel art, or images you’ll re-edit).