Pick the wrong image format and you either end up with a needlessly huge file or a picture that looks blurry and blocky. Pick the right one and you get crisp images that load fast and work everywhere they need to. But with four common choices — PNG, JPG, WebP, and AVIF — it is easy to feel unsure which is best. This guide compares all four in plain English, so you can confidently choose the right format for photos, graphics, and the web.
The four formats at a glance
Here is the quick version. JPG is the universal format for photographs — small files, opens everywhere, no transparency. PNG is for graphics and anything that needs a transparent background or razor-sharp edges, at the cost of large files for photos. WebP is a modern all-rounder that beats both JPG and PNG on file size while supporting transparency and animation. AVIF is the newest of the bunch and usually produces the very smallest files, though it asks for a little more in return. The rest of this article explains when each one is the right call.
JPG: the universal photo format
JPG (or JPEG) has been the default photo format of the internet for decades, and for good reason. It compresses photographs efficiently, producing reasonably small files that look good, and — crucially — it opens on essentially every device, browser, and app ever made. Its weaknesses are that it is lossy (it discards some detail to save space), it cannot store a transparent background, and at low quality settings it shows blocky artefacts and colour banding. For ordinary photographs that need to work absolutely everywhere, JPG remains the dependable choice.
PNG: for graphics and transparency
PNG is lossless, meaning it preserves every pixel exactly, and it supports full transparency. Those two traits make it perfect for logos, icons, diagrams, screenshots, and any graphic with text or hard edges that must stay crisp. The downside is size: because it never throws anything away, PNG produces very large files for photographs, where all that preserved detail brings no visible benefit. The rule of thumb is simple — reach for PNG when you have flat graphics or need transparency, and avoid it for photos.
WebP: the modern all-rounder
WebP, developed by Google, was designed to replace both JPG and PNG. It offers lossy and lossless modes, supports transparency like PNG and animation like GIF, and is typically 25–35% smaller than a JPG of equivalent quality. Best of all, every current browser now supports it, so the old compatibility worries have largely faded. For website images, WebP is often the smartest default: you get smaller files, faster pages, and the flexibility to handle both photos and transparent graphics with a single format.
AVIF: the smallest files, with caveats
AVIF is the newest format here, based on the AV1 video codec, and it is the current champion of compression. At the same visual quality, AVIF files are frequently smaller than WebP and dramatically smaller than JPG, and it supports transparency, animation, and a wider colour range. The caveats are modest but real: creating AVIF files can be slower than other formats, and while browser support is now broad, it is still a touch behind WebP and JPG in the very oldest software. AVIF is an excellent choice when squeezing out every last kilobyte genuinely matters — for example on an image-heavy website where speed is critical.
Which format should you choose?
A simple decision guide covers almost every situation. For photographs on a modern website, use WebP, or AVIF if maximum efficiency is the priority. For photographs that must open in any app, anywhere, use JPG. For logos, icons, screenshots, and graphics with transparency or sharp edges, use PNG — or WebP if you want a smaller transparent file and only need it on the web. When in doubt, WebP is the most versatile single answer, with JPG as the safe fallback for universal compatibility. Match the format to where the image will live and what it contains, and you will rarely go wrong.
How to convert between formats privately
Once you know which format you want, you need to get there. Our image converter lets you convert between JPG, PNG, WebP, and AVIF in a couple of clicks, and because it runs entirely in your browser, your images are never uploaded to a server. If you also want to shrink a file as you go, the image compressor can compress and re-encode photos locally so they look great at a fraction of the size. Both tools are free, private, and need nothing installed — choose the right format and the right size without ever giving up control of your images.
Frequently asked questions
Is WebP better than JPG? For most web images, yes. WebP files are typically 25–35% smaller than JPG at the same quality and also support transparency and animation. JPG still wins when you need a file that opens in absolutely every old app.
Should I use AVIF or WebP? AVIF usually produces the smallest files of all and supports modern features, but it can be slower to create and is slightly less universally supported than WebP. WebP is the safer everyday choice; AVIF is great when squeezing out every last kilobyte matters.
When should I use PNG instead of JPG? Use PNG for logos, icons, screenshots, and anything that needs a transparent background or perfectly sharp edges. Use JPG for photographs, where PNG would create a much larger file for no visible benefit.