Why PNG Is the Wrong Default for Photos
PNG is a lossless format. Every pixel is preserved exactly as it was captured. For logos, icons, illustrations with solid colors, and images that need a transparent background, PNG is genuinely the best choice available. For photographs, it is almost always the wrong one. A photo saved as PNG is typically four to six times larger than the same photo saved as a high-quality JPEG. For a site with 50 photos, that is the difference between a 5MB page and a 25MB page.
I learned this when I audited my portfolio site and found 34 project images, all PNG, averaging 4.1MB each. My contact page, which featured a single background photograph, was 6.2MB on its own. I had optimized my CSS, minified JavaScript, added a CDN, and purchased a premium hosting plan. But the format issue alone was eating every one of those gains and then some. I had been solving the wrong problem for months.
Understanding Each Format and When to Use It
- PNG: Best for logos, icons, screenshots, and images that need a transparent background. Produces very large files for photographs because it stores every pixel losslessly.
- JPEG: Best for photographs and images with complex gradients or color blends. Good quality at reasonable file sizes. Supported by 100% of browsers and devices.
- WebP: Best for almost everything on the modern web. Achieves better visual quality than JPEG at 25 to 35% smaller file sizes. Supported by over 97% of browsers as of 2026.
- SVG: Best for icons and simple illustrations built from geometric shapes. Scales perfectly at any size. Cannot be used for photographs.
WebP is now supported by over 97% of browsers worldwide. If you are still avoiding WebP because you remember it as an 'experimental' format, that information is outdated. The adoption barrier that existed in 2019 no longer exists in 2026.
A Simple Rule for Choosing the Right Format
The decision framework I now use is simple. Does the image need a transparent background? If yes, use PNG. Is it a photograph or an image with complex color gradients? If yes, use WebP as your first choice. Is WebP not an option for some specific reason? Fall back to JPEG, never to PNG. Is it a simple icon or geometric illustration? Consider SVG first, then PNG.
For most web projects, converting your photographs from PNG or JPEG to WebP is the single highest-impact optimization you can make without touching any code. The JPEG to WebP converter and the PNG to WebP converter make this a matter of seconds per image. The format question that felt complicated for years turns out to have a very simple answer in almost every real-world scenario.
Where to Start With Your Existing Image Library
Start with your highest-traffic pages first. If you have 50 pages and 5 of them receive 80% of your traffic, optimize those 5 first and measure the result before working through the rest of the archive. For images that need to stay as JPEG for compatibility reasons, run them through the JPEG compressor at minimum. You will often find a 30 to 50% file size reduction with no perceptible quality difference.
And if you ever need to convert in the other direction for a client or a tool that requires JPEG specifically, the WebP to JPEG converter handles that in one click. Format decisions do not need to be permanent. What matters is starting with the right choice for each context and knowing you can change it whenever your requirements shift.