JPG, PNG, WebP or AVIF: which image format should you use?

Every image format is a compromise between file size, visual quality and compatibility. Picking the wrong one is how you end up with a 9 MB screenshot, a logo surrounded by an ugly white box, or a photo that won't open on a colleague's laptop. This guide explains what each of the four common formats is actually good at, with concrete examples from the files people convert most often.

JPG: the universal photo format

JPG (or JPEG) has been the default for photographs since the 1990s. It uses lossy compression: it throws away detail that the eye is unlikely to notice, especially in smooth gradients and busy textures. A 12-megapixel phone photo typically lands between 2 and 5 MB as a JPG at high quality, and can drop below 500 KB at medium quality with little visible change on a screen.

• Best for: photographs, scanned colour documents, anything you need to open everywhere.
• Avoid for: screenshots with text, logos, line drawings — JPG creates fuzzy “ringing” around sharp edges.
• No transparency: transparent areas become a solid colour, usually white.

Each time you re-save a JPG, a little more detail is lost. Keep an original and export copies from it rather than editing the same JPG repeatedly.

PNG: sharp edges and transparency

PNG is lossless — every pixel is stored exactly. That makes it ideal for screenshots, interface mock-ups, diagrams and logos, where crisp edges and readable small text matter. PNG also supports full transparency, which is why logos are usually distributed as PNG files.

The cost is size. A photograph saved as PNG is often three to five times larger than the same photo as a high-quality JPG, with no visible benefit. If someone sends you a 15 MB PNG holiday photo, converting it to JPG or WebP is an easy win.

WebP: the modern all-rounder

WebP was designed for the web and supports both lossy and lossless compression plus transparency. At comparable visual quality, lossy WebP files are commonly 25–35% smaller than JPG. Every current version of Chrome, Edge, Firefox and Safari displays WebP, which makes it a safe default for website images.

The remaining friction is outside the browser: some older desktop editors, email clients and print shops still don't accept WebP. If you download a WebP image and can't open it, converting it to JPG solves the problem in seconds.

AVIF: smallest files, slower to create

AVIF is the newest of the four. It often beats WebP by another 20–30% at the same quality, and handles gradients and dark scenes particularly well. Encoding is computationally heavy, so converting a large batch takes noticeably longer, and not every browser can save AVIF yet — PDFQuick's Image Converter only offers it when your browser supports it.

Quick decision guide

1. Photo you'll email or print, or must open anywhere: JPG at 80–90% quality.
2. Screenshot, chart, logo or anything with transparency: PNG.
3. Image for your own website: WebP, or AVIF if you control the build and want the smallest files.
4. Image someone else must edit in older software: JPG or PNG.

Converting without losing more than necessary

Converting from a lossy format (JPG, lossy WebP, AVIF) to another lossy format compounds the loss slightly, so always convert from the best original you have. Converting to PNG never adds loss but won't restore detail that was already discarded. For resizing and converting at the same time, resize first to the size you actually need — a 4000-pixel image shown at 800 pixels wastes most of its bytes.