JPG, PNG and WebP are the three image formats you'll meet most often online, and AVIF is the fast-rising fourth. They are not interchangeable — each was designed for a different job, and using the wrong one means either a bloated file or a blurry image. This guide explains how each format actually compresses, backs it up with Google's own published numbers, and gives you a one-line rule for every situation.
How the four formats compare
| Format | Compression | Transparency | Best for | Browser support |
|---|---|---|---|---|
| JPG / JPEG | Lossy | No | Photographs, form uploads | Universal |
| PNG | Lossless | Yes (alpha) | Logos, icons, screenshots, text | Universal |
| WebP | Lossy + lossless | Yes (alpha) | Website images, all-round use | ~97% of users |
| AVIF | Lossy + lossless | Yes (alpha) | Cutting-edge web performance | ~94% of users |
JPG — the right default for photographs
JPG (also written JPEG) uses *lossy* compression: it discards detail the human eye barely registers to produce a small file. That trade is excellent for photographs, where smooth gradients hide the loss, which is why JPG is the default for almost every upload form and camera. Its limitations are that it has no transparency, and that every time you re-save a JPG it loses a little more quality (so keep an original and avoid editing the same JPG repeatedly).
If a portal asks for a specific file size — say a passport photo under 50KB — JPG is the format that gets you there cleanly. Convert anything to JPG with our Image to JPG converter, or hit an exact target with a tool like Compress Image to 50KB.
PNG — for graphics, text and transparency
PNG is *lossless*, so it reproduces every pixel exactly, and it supports an alpha channel for transparency. That makes it the correct choice for logos, icons, UI screenshots, diagrams and anything with sharp edges or text — content where JPG's lossy artefacts would show as ugly halos around the lines. The trade-off is weight: a full-colour photograph saved as PNG is often five to ten times larger than the same photo as JPG, because lossless compression can't throw anything away.
WebP — the modern all-rounder
WebP, developed by Google, is the format that finally does everything: it offers both lossy and lossless modes and supports transparency. According to Google's own comparative studies, lossy WebP files are 25–34% smaller than equivalent JPEGs at the same quality (measured by SSIM), and lossless WebP is about 26% smaller than PNG. That is a meaningful, free reduction in page weight — which is why WebP became the default for performance-focused sites.
“WebP lossless images are 26% smaller in size compared to PNGs. WebP lossy images are 25–34% smaller than comparable JPEG images at equivalent SSIM quality index.”
Compatibility is no longer a real concern: WebP is supported by roughly 97% of browsers in use, including every current version of Chrome, Safari, Firefox and Edge. The only holdouts are very old software. For images you control on your own site, converting your library to WebP with our Image to WebP tool is one of the simplest speed wins available.
What about AVIF?
AVIF is the newest format and compresses even harder than WebP — often around 50% smaller than JPEG for photographic content — with support for transparency and HDR. The catch in 2026 is reach: AVIF sits at roughly 94% browser support versus WebP's ~97%, with the gap coming from older Android and iOS devices. The professional approach is to serve AVIF with a WebP (and JPG) fallback via the HTML `<picture>` element, so modern browsers get the smallest file and everyone else still sees an image.
Why the format you pick affects your Google ranking
Images are usually the heaviest assets on a page, so format choice directly shapes your Largest Contentful Paint — one of Google's Core Web Vitals and a confirmed ranking signal. Shipping WebP or AVIF instead of unoptimised JPG/PNG can cut image weight by a third or more, which shows up as faster loads on mobile networks. Pair the right format with sensible dimensions and compression for the biggest gain.
Quick decision guide
- Uploading a photo to a form or portal → JPG
- Logo, icon, screenshot, or anything with transparency → PNG (or WebP if it's for the web)
- Photos and graphics on your own website → WebP for the best size-to-quality ratio
- Squeezing every last kilobyte, with a fallback → AVIF + WebP via `<picture>`
- You just need it to open everywhere → JPG
Whichever you need, you can convert between all three for free with our Image to WebP, Image to JPG and Image to PNG tools. Everything runs in your browser — your files are never uploaded or stored, and there's no sign-up.
Frequently asked questions
- Is WebP better than JPG?
- For images on a website, yes — WebP produces files 25–34% smaller than JPG at the same visual quality, and it supports transparency. For uploading to a form that expects a JPG, stick with JPG for compatibility.
- Does converting JPG to WebP lose quality?
- Lossy WebP discards a small amount of detail like JPG does, but at the same quality setting it does so more efficiently, so the visible result is comparable while the file is smaller. For a pixel-perfect copy, use lossless WebP or PNG.
- Should I use WebP or AVIF in 2026?
- Use WebP as your reliable default (~97% support). Add AVIF as a primary source with a WebP fallback via the <picture> element when you want maximum compression and can spare the setup — AVIF is smaller but reaches a few percent fewer users.
- Can I convert WebP back to JPG or PNG?
- Yes. Use our WebP to JPG or Image to PNG tools. Note that converting a transparent WebP to JPG replaces transparent areas with a solid background, since JPG has no transparency — convert to PNG to keep it.