JPG vs PNG vs WebP vs AVIF in 2026 — Which Image Format, and When

2026-06-28

People ask me which image format is "best" more than almost anything else. There isn't one — each format is a trade between file size, quality, and transparency, and the right pick depends on the picture. Here's how I think about the four that actually matter in 2026. You can convert between all of them here without uploading anything.

The short version

• Photos → JPG (safe everywhere) or AVIF (much smaller, if you control where it's shown).
• Logos, icons, screenshots, anything with sharp edges or transparency → PNG, or WebP to save space.
• Web images where you control the page → AVIF first, WebP as the fallback.
• Sending a file to someone who just needs to open it → JPG or PNG. Boring, but they'll never have a problem.

JPG — the universal default

JPG (or JPEG) is lossy: it throws away detail you mostly can't see to get small files. It's been around forever, so everything opens it — every phone, every printer, every ancient laptop. The downsides: no transparency, and it gets blocky if you save the same JPG over and over or push the compression too hard. It's also bad at sharp edges, so text and line art look fuzzy.

Use it for: photographs, anything you're emailing or handing off, anywhere you want zero compatibility risk.

PNG — lossless and transparent

PNG is lossless — it keeps every pixel exactly — and supports an alpha channel (transparency). That makes it perfect for logos, icons, screenshots, and graphics with hard edges. The cost is size: a PNG photo can be 5–10× larger than the same JPG, because photos have too much detail to store losslessly cheaply.

Use it for: logos, icons, UI screenshots, diagrams, anything that needs a transparent background or crisp text.

WebP — the modern middle ground

WebP does both jobs: lossy and lossless, with transparency, usually smaller than the JPG or PNG equivalent. Every current browser supports it. The main friction is outside the browser — some older desktop apps and a few messaging tools still don't open WebP, so it's a "for the web" format more than a "send it to grandma" format.

Use it for: images on a website you control, where smaller files mean faster pages.

AVIF — smallest, newest

AVIF is the newest of the four and typically the smallest at a given quality, especially for photos. It also handles transparency and a wider color range. The trade-off is the same as WebP but more so: support is good in modern browsers but spottier in older software, and encoding it is slower. It's worth it when bandwidth matters and you serve a WebP or JPG fallback.

Use it for: web photos where you want the smallest possible file and can provide a fallback.

A rule that almost always works

If a human needs to open the file, use JPG (photos) or PNG (graphics). If a browser needs to load the file, reach for AVIF or WebP and keep a JPG/PNG fallback.

Transparency forces your hand: JPG can't do it, so anything with a see-through background has to be PNG, WebP, or AVIF.

Converting without uploading

Switching formats shouldn't mean handing your photos to a server. ToolKoala's image converter does the whole thing in your browser — drop a file (or a whole batch), pick the target format, download. The pixels never leave your device. If you're prepping icons, the favicon generator and SVG to PNG tools follow the same rule.

FAQ

Which image format is the smallest? For photos, AVIF is usually the smallest at a given quality, followed by WebP, then JPG. For flat graphics with few colors, a well-optimized PNG or WebP can beat them. Size always depends on the actual image, so the honest answer is "convert it and compare."

Is WebP better than JPG? For images on the web, usually yes — WebP files are typically smaller at the same quality and support transparency. But JPG opens in more places, so for files you send to people, JPG is still the safer choice.

When should I use PNG instead of JPG? Whenever you need transparency or crisp edges — logos, icons, screenshots, diagrams, text. PNG is lossless, so it won't get blocky, but photos saved as PNG will be much larger than as JPG.

Will I lose quality converting between formats? Converting to a lossy format (JPG, lossy WebP/AVIF) discards some detail. Converting between lossless formats (PNG ↔ lossless WebP) doesn't. Re-saving a JPG repeatedly slowly degrades it, so keep an original if you can.

Do these conversions upload my images? Not on ToolKoala — the converter runs entirely in your browser, so your files stay on your device.

— Milo 🐨