PNG vs. JPEG vs. WebP: Differences and When to Use Each Image Format

The character of the three formats

The core differences come down to two points: lossless or lossy, and whether transparency is supported. PNG compresses without discarding any information, so the image quality is perfect, but photos end up large. JPEG shrinks files by discarding information the human eye barely notices, which is very efficient for photos, but on diagrams and text with sharp edges, noise (mosquito noise) becomes noticeable.

How to choose when you're unsure

• Need transparency → PNG or WebP (JPEG is not an option)
• Photo, and you just want it light → WebP, then JPEG
• Logo, diagram, or screenshot with text → PNG or lossless WebP
• The recipient's environment is old or unknown (sending to a print shop, an older internal business system, etc.) → PNG or JPEG
• Images for a website → WebP as the first choice

WebP is supported by all major browsers, so it is basically the first choice for images shown on the web. On the other hand, some apps and systems still can't import it. Remember “WebP for the web, PNG/JPEG for files you hand over,” and you won't go wrong.

What quality setting is appropriate?

JPEG and WebP have a quality setting. The closer to 100, the less degradation; the lower it is, the lighter the file. Practical guidelines are as follows.

How to convert in your browser

1. 1

   Select an image

   Choose an image file you have, such as PNG, JPEG, or WebP. Photos from your smartphone work as is.

2. 2

   Choose the output format

   Pick PNG, JPEG, or WebP. Use the guidelines above as a reference.

3. 3

   Adjust the quality

   The quality slider is enabled for JPEG and WebP. PNG uses lossless compression, so it has no quality setting.

4. 4

   Compare sizes before and after, then download

   The converted file size and how much it was reduced are shown. If you don't get the result you expected, try again with a different format or quality.

All conversion happens inside your browser, so your images are never uploaded to a server.

Things to watch out for when converting

• Converting to JPEG removes transparency. Transparent areas are filled with white, so choose PNG or WebP if you want to keep transparency.
• Lossy compression can't be undone. Converting JPEG → PNG doesn't restore lost information; it only makes the file bigger.
• Repeated recompression accumulates degradation. The basic rule is to save intermediate editing files in a lossless format such as PNG and convert to a lossy format only at the final export step.
• Always keep the original image. That way you can re-export later in a different format or quality.

A common misconception is that “converting to PNG makes it high quality.” PNG is a format that doesn't degrade images; it doesn't restore images that have already degraded. To get better quality, you need to go back to the original data, not convert.

Where AVIF, HEIC, GIF, and SVG fit in

Not every image you receive is PNG, JPEG, or WebP. Photos taken on an iPhone are HEIC, and images saved from the web are increasingly AVIF. Knowing what each format was made for helps you decide quickly whether to convert.

The steps for converting AVIF when it won't open are in how to handle AVIF files, how to make iPhone HEIC photos open on Windows is in how to convert HEIC to JPEG, and troubleshooting WebP that won't open is in what to do when WebP won't open. SVG logos work in a fundamentally different way, so they are covered separately in how SVG differs from PNG and JPEG.

What to check when converting doesn't reduce file size

“I changed the format but it barely got lighter” is a common problem. In most cases the cause is not the format but the size or content of the image itself.

• Too many pixels: a 4000 px-wide photo is used as is. Shrinking it to the width actually needed for display has a much bigger effect
• A photo saved as PNG: photos contain a lot of information that lossless compression can't reduce. Change it to JPEG or WebP
• A diagram or screenshot saved as JPEG: images with many flat areas can be smaller as PNG
• Recompressing an already compressed image: there's nothing left to trim

FAQ

Should I use PNG or JPEG?

JPEG is best for photos; PNG is best for images with sharp edges such as logos, diagrams, and screenshots, or for images that need transparency. Because JPEG uses lossy compression, noise becomes noticeable around text and thin lines.

How much lighter does converting to WebP make an image?

It depends on the content, but many reports show files about 20–30% smaller than JPEG at similar visual quality. The effect varies a lot from image to image, though, so the reliable way is to actually convert and compare sizes.

Does converting reduce image quality?

Converting to PNG uses lossless compression, so that step causes no degradation. With lossy settings in JPEG or WebP, quality degrades according to the quality value. At around 85, you will rarely notice a difference in normal viewing.

Does the Image Format Converter upload my images?

No. All conversion is done inside your browser, and image files are never sent to a server.

How can I make a file lighter while keeping transparency?

Choose WebP. WebP supports transparency and can also apply lossy compression, so it can be much lighter than a transparent PNG. If the recipient doesn't support WebP, the practical option is to keep it as a transparent PNG and reduce the pixel count.

Should I convert to AVIF?

For images on your own website, it's a strong option. For files you hand to someone else, however, some environments still can't open it, so it's safer to avoid. When you don't know who will receive it, JPEG or PNG is the safe choice.