Where PNG, JPG and WebP came from, where they're used today, and how good they actually are.
PNG was created in 1996 as a free, open replacement for GIF, after Unisys began enforcing patent royalties on GIF's underlying LZW compression algorithm. A group of graphics developers designed PNG from scratch to be patent-unencumbered, and it quickly became a W3C-recommended standard. Unlike GIF's 256-colour palette, PNG supported full 24-bit colour and true alpha transparency from day one.
Today PNG is the default choice for anything that needs pixel-perfect accuracy: logos, icons, screenshots, UI mockups, diagrams, and any image with transparency or sharp text/edges. It's the standard export format across design tools like Figma and Photoshop when fidelity matters more than file size.
PNG is always lossless — it reproduces the exact original pixels, every time, with no generational quality loss even after repeated re-saves. It compresses using the DEFLATE algorithm (the same family used by ZIP and gzip), preceded by per-row filtering that predicts each pixel from its neighbours to make the data more compressible. The trade-off is size: because it doesn't discard any information, PNG files for photographic content are typically several times larger than an equivalent JPEG or WebP.
Published in 1992 by the ISO/CCITT committee that gave the format its name, JPEG was designed specifically to make continuous-tone photographs practical to store and transmit at a time when disk space and modem bandwidth were both extremely limited. Its arrival coincided with, and helped enable, the rise of digital cameras and the early photographic web.
JPEG remains the default format for photographs across the web, social media, e-commerce product imagery, and virtually every digital camera and phone. Its near-universal compatibility, going back three decades, makes it the safest choice when you can't control what will open the file.
JPEG is a lossy format: it splits an image into 8×8 pixel blocks, converts each block into frequency data using a Discrete Cosine Transform, then discards the frequency detail the human eye is least sensitive to via a quantization step — this is exactly what a "quality" setting controls. At high quality (85–95%) the loss is generally imperceptible; below roughly 50% you start to see blocky artifacts and colour banding. JPEG has no transparency channel and handles sharp edges or text poorly compared to PNG.
WebP was released by Google in 2010, built on the intra-frame keyframe coding from the VP8 video codec that Google acquired along with On2 Technologies. It was designed explicitly to be a smaller, modern alternative to both JPEG and PNG for web delivery, and later gained a dedicated lossless mode and animation support, filling GIF's role too.
WebP has become the format of choice for web performance: image CDNs and frameworks (Cloudinary, imgix, Next.js Image, and others) increasingly auto-convert uploads to WebP for faster page loads and better Core Web Vitals scores. Every major modern browser — Chrome, Firefox, Edge, and Safari since version 14 — supports it natively.
WebP supports both modes in one format. Lossy WebP uses predictive block coding similar in spirit to JPEG but more efficient, typically producing files 25–35% smaller than JPEG at equivalent visual quality, and it supports an alpha channel that JPEG lacks. Lossless WebP uses image-specific prediction and colour transforms on top of its own LZ77-style compression, and typically beats PNG by around 26% at identical quality with no loss at all. The trade-off is that, being newer, it has slightly less support in older third-party tools and legacy software than JPEG or PNG.
Curious about file size specifically? See how each format compresses.