WebP vs JPG vs PNG: which image format should you use?

JPG, PNG and WebP are the three image formats you run into every day. They all display a picture, but they store it in very different ways, and picking the wrong one leads to blurry logos, bloated pages or images that simply will not open in the program you need. This guide explains the differences and gives you a clear rule for every common situation.

The short answer

• JPG for photos, when you need maximum compatibility.
• PNG for logos, icons, screenshots and anything that needs sharp edges or transparency.
• WebP for images on a website, where smaller files mean faster pages.

The rest of this article explains why.

Lossy vs lossless compression

The most important difference is how each format compresses the image.

• JPG is lossy. It throws away detail the eye is unlikely to notice, which makes photos small. The cost is that sharp edges and flat colours develop blocky or blurry "artefacts", and every time you edit and re-save a JPG you lose a little more quality.
• PNG is lossless. Every pixel is stored exactly. That is perfect for text, lines and flat areas of colour, but a photo saved as PNG is usually several times larger than the same photo as a JPG.
• WebP does both. It has a lossy mode that competes with JPG and a lossless mode that competes with PNG. For the same visual quality, WebP files are typically smaller than their JPG or PNG equivalents, which is exactly why it was designed for the web.

A useful consequence: converting a JPG to PNG does not bring back the detail JPG discarded. It only stops further losses if you plan to keep editing the image.

Transparency

• JPG has no transparency. Transparent areas become a solid colour, usually white or black.
• PNG supports a full alpha channel, including soft, semi-transparent edges. It is the classic choice for logos placed on coloured backgrounds.
• WebP also supports alpha transparency, in both lossy and lossless mode.

If you convert a transparent PNG or WebP to JPG, the transparent parts will be filled in. Keep that in mind before you send a logo as a JPG.

Animation

JPG and standard PNG are still images. WebP can also store animation, making it a lighter alternative to GIF for short loops. If you convert an animated WebP to JPG or PNG, you get a single still frame, not the animation.

Browser and software support

JPG and PNG open everywhere: every browser, every operating system, every image editor, every messaging app, every printer driver. WebP is supported by all current major browsers, and most modern operating systems and editors can open it, but you will still find older software, some upload forms and some print services that reject it. That is the most common reason people convert a WebP to JPG: a downloaded image that a program refuses to open.

File size and web performance

On a website, image weight matters. Large images slow down loading, especially on mobile connections, and page speed affects both visitors and search rankings. Some practical rules:

• Serve photos as WebP (lossy) or, if you need the widest compatibility, as a well-compressed JPG.
• Serve logos, icons and UI graphics as WebP (lossless) or PNG, or as SVG if you have a vector version.
• Never upload a photo as PNG just because it is "higher quality". The visitor will not see the difference, but they will wait for it.
• Resize images to the size they are actually displayed. No format can compensate for a 4000-pixel photo shown in a 400-pixel box.

Which format to choose, case by case

• Photos from a camera or phone: JPG for sharing and printing, WebP for your website.
• Logos and icons: PNG or lossless WebP, both keep transparency and crisp edges.
• Screenshots: PNG. Text and interface elements stay razor sharp; JPG smears them.
• Illustrations with flat colours: PNG or lossless WebP.
• Short animations: animated WebP instead of a heavy GIF.
• Images for an email, a form or an older program: JPG or PNG, because they are universally accepted.

Converting between them

You do not have to redo anything to switch formats. Azpy's image converters run entirely in your browser: your images are processed on your own device and are never uploaded to a server. Turn a WebP into a JPG when a program refuses it, a PNG into WebP to lighten your website, or a JPG into PNG before further editing. The free limit for these browser tools is 25 MB per file, and you can find every converter in the tools directory.

A rule of thumb

Photo? JPG or WebP. Sharp edges or transparency? PNG or WebP. For the web, prefer WebP; for everything else, pick whatever the destination accepts.