PNG vs WEBP vs AVIF: Which Image Format Should You Actually Use?

Every few years a “better” image format shows up promising smaller files without a quality hit. WEBP made that promise around 2010, and AVIF is making it again now. PNG, meanwhile, refuses to go anywhere because it does one thing better than either of them. Here’s how the three actually compare.

The short version

• PNG — best for images that need lossless quality or transparency and aren’t photographs: screenshots, logos, icons, graphics with sharp edges or text.
• WEBP — the safe modern default for photos on the web. Smaller than JPG at equivalent quality, supports transparency, and works in every browser released in the last several years.
• AVIF — the smallest files of the three at a given quality level, especially for photos, but slower to encode and still catching up on tooling and support in some older software.

File size

For photographic images, AVIF typically produces the smallest files, often 20–50% smaller than WEBP at visually similar quality, which itself is usually 25–35% smaller than an equivalent JPG. PNG is the odd one out here: because it’s lossless, PNG files of photos are often larger than a JPG, WEBP, or AVIF of the same image, sometimes dramatically so. PNG only wins on size for flat-color graphics like logos or UI screenshots, where its lossless compression has less work to do.

Quality and transparency

All three formats support transparency (alpha channels), which rules out JPG for logos or overlays. Where they differ:

• PNG is lossless — zero compression artifacts, at the cost of larger files.
• WEBP supports both lossless and lossy modes, so you can choose per image.
• AVIF also supports both modes and generally produces cleaner results than WEBP at very low bitrates, though the difference is subtle at normal quality settings.

Compatibility

This is where the decision usually gets made in practice. PNG works absolutely everywhere and always has. WEBP is supported by every major browser (Chrome, Firefox, Safari, Edge) as of several years ago, so compatibility concerns are largely historical at this point. AVIF support is also strong in current browsers, but a few older devices, some email clients, and certain content management systems and design tools still don’t handle it — worth checking if you’re publishing somewhere outside a modern browser.

So which one should you pick?

• Uploading a photo to a website or app: WEBP is the safest choice — smaller than JPG, broadly supported, no surprises.
• Squeezing out the smallest possible file size and you control the pipeline: AVIF, provided wherever you’re displaying it actually supports it.
• Logos, icons, screenshots, or anything with transparency and sharp edges: PNG, or WEBP in lossless mode if file size matters.
• Sending a photo to someone or uploading to an old system with unknown format support: stick with JPG or PNG — the formats every piece of software has understood for decades.

You don’t have to commit to one format for your whole library. It’s common to keep source images as PNG, then generate WEBP or AVIF versions for anything you publish. Convert JPG to PNG, JPG to WEBP, or JPG to AVIF directly in your browser, or run existing images through an image compressor if you just need smaller files without changing format.