JPG vs PNG: Which Format Should You Use When?

You want to save or upload an image, and the program asks: JPG or PNG? Or the job application portal rejects your screenshot because it’s too big. The answer is usually simple once you know what each format does well and what it doesn’t.

JPG vs PNG compared

Which format for which purpose?

What is JPG?

JPG, short for JPEG, has been around since 1992. It’s the standard format for photos. JPG saves space by leaving out details your eye barely notices. With photos and their soft transitions, you don’t see it. With sharp edges, like text or lines, you get ugly smudges and fringes instead.

What is a PNG file?

PNG stands for “Portable Network Graphics” and has been around since 1996. A PNG file stores every pixel exactly as it is, so without any loss. To do this, it uses a method that packs repeating patterns into less space. That works very well for areas of a single color, like in screenshots or logos. With photos and their millions of different colors, it barely works.

PNG can also store transparent areas. That’s why logos and icons almost always come as PNG. There’s PNG-8 with at most 256 colors for simple graphics, and PNG-24 with full color.

A real file size test

We converted the same images with Filemanta (October 2026):

• A photo: 1.0 MB as PNG, 206 KB as a high-quality JPG. The JPG is five times smaller and looks the same.
• A simple graphic: 3.7 KB as PNG, 20 KB as JPG. Here the JPG is bigger, and the edges get blurry.

That shows you the rule of thumb: photos belong in JPG, graphics in PNG.

What happens when you convert

PNG to JPG: For photos, the file gets much smaller. JPG has to fill transparent areas with a color. Many programs use black, and your logo suddenly sits in a black box. With PNG to JPG you choose white or black yourself and set the quality in three levels. You can convert many images at once.

JPG to PNG: The image doesn’t get better. What was lost when saving as JPG stays lost. The file usually gets four to six times larger. This only makes sense if a program or form asks for PNG or you want to edit the image often. That’s what JPG to PNG is for.

Just renaming the extension doesn’t work in either direction. The guide How to change a file extension explains why.

Why JPG gets worse every time you save

Every time you open a JPG, edit it and save it as JPG again, it gets compressed again. After a few rounds, you see smudges at edges and in areas of a single color. Here’s how to avoid that:

• Keep the original and always edit a copy.
• Save in-between versions as PNG and only the final result as JPG.
• Choose high quality when saving as JPG.

What about WebP, HEIC and AVIF?

Besides JPG and PNG, you’ll come across three newer formats:

For sending and uploading, JPG and PNG remain the safe choice. What exactly HEIC is, is explained in the guide What is a HEIC file.

• Rule of thumb: photos as JPG; screenshots, logos, text and transparency as PNG.
• JPG compresses with loss, which keeps files small. PNG saves without loss.
• Only PNG supports transparent areas. JPG fills them with a color.
• A photo saved as PNG is often five times larger than as JPG.
• Converting JPG to PNG doesn't make an image sharper, just the file bigger.
• JPG loses a little quality every time you save it again, so keep the original.