What is a PNG?
PNG stands for Portable Network Graphics. Unlike JPG, PNG uses "lossless" compression, meaning it preserves every single pixel of your image without discarding any data. The result is a file that looks exactly as sharp as the original—no fuzziness, no artifacts—but takes up more disk space than a compressed JPG. PNG was created in the mid-1990s as an open, patent-free alternative to GIF, and today it is one of the two dominant image formats on the web.
How PNG Compression Works
PNG uses a compression algorithm called DEFLATE. Rather than throwing away image data the way JPG does, DEFLATE finds repetitive patterns in the pixel data and represents them more efficiently—think of it like a zip file for your image. When you unzip it (open the file), every pixel is reconstructed perfectly. This means you can save and re-save a PNG file hundreds of times without any loss of quality, which is simply not possible with JPG.
A key feature of PNG that JPG completely lacks is the alpha channel—a fourth layer of data that controls the transparency of each pixel. This is what gives logos and icons their transparent backgrounds, allowing them to sit cleanly over any colored surface without a white or colored box behind them.
When to Use a PNG
PNG is the right choice for synthetic or graphical content where sharpness and precision matter:
- Screenshots: Operating systems default to PNG for screenshots because the text, icons, and UI elements remain pixel-perfect.
- Logos and Icons: Flat colors, sharp edges, and transparent backgrounds make PNG ideal for brand assets.
- Digital Art and Illustrations: Line art, pixel art, and illustrations with solid fills all benefit from lossless storage.
- Transparent Backgrounds: Any image that needs to sit cleanly on top of another surface requires the alpha channel that only PNG (and WebP) offer.
- Technical Diagrams and Charts: Graphs, flowcharts, and annotated screenshots must stay crisp—JPG compression would blur the text labels.
When NOT to Use a PNG
Avoid PNG for standard real-world photography on websites. A full-color photo saved as PNG is typically three to five times larger than the same photo saved as a JPG at high quality. That bloated file size translates directly into slower page load times, which hurts both user experience and SEO. For photos without transparency, JPG (or modern WebP) is almost always the better choice.
PNG is also a poor choice for very large print-ready documents. If you are preparing artwork for a print shop, the native formats of your design application (AI, PSD, or PDF) are more appropriate.
PNG vs JPG vs SVG
The three formats serve different purposes. JPG excels at compressing photographic images—millions of subtle color gradients—where a small amount of pixel degradation is imperceptible. PNG excels at crisp graphics with flat colors, text, and transparent backgrounds. SVG (Scalable Vector Graphics) is a completely different animal: it stores shapes as mathematical equations rather than pixels, making it infinitely scalable for logos and icons. The trade-off is that SVG cannot represent photographs at all.
Frequently Asked Questions
Can I convert a JPG to PNG to recover the quality I lost?
Unfortunately, no. When a JPG is saved, the discarded pixel data is gone permanently. Converting that JPG to PNG gives you a lossless container for an already-degraded image. You will not recover the lost sharpness; you will just end up with a larger file. Always save from the original source in PNG if quality is the priority.
Why is my PNG file so much larger than the same image saved as a JPG?
Because PNG stores every pixel without discarding any information. For a complex photograph with millions of subtly different colors, DEFLATE compression cannot find enough repeating patterns to shrink the file significantly. JPG solves this by first simplifying (and losing) color information before compressing. For photos, that trade-off is usually worthwhile; for flat-color graphics, it is not.
What is the difference between PNG-8 and PNG-24?
PNG-8 stores a maximum of 256 colors and is similar in concept to the old GIF format—it is tiny but limited. PNG-24 stores up to 16.7 million colors and supports full alpha transparency. For most modern uses (logos, screenshots, illustrations) you want PNG-24. PNG-8 is mostly a legacy option for simple web graphics where file size is critical.
PNG Tools
- PNG to PDF — Collect all your high-resolution screenshots or graphics into a single, shareable PDF document.
- PDF to PNG — Extract any page from a PDF as a lossless PNG—perfect for pulling a chart or diagram into a presentation.