Image Format Guide: JPG, PNG, WebP, AVIF, HEIC & ICO
Every image format is a trade-off between quality, file size, and compatibility. This guide explains what each one is best at — and when you're ready, our free image converter switches between them instantly, right in your browser.
In a hurry? Photos to share → JPG. Logos or transparency → PNG. Smaller files for the web → WebP or AVIF. iPhone photo → convert HEIC to JPG. Website icon → ICO.
The formats at a glance
| Format | Best for | Transparency | Notes |
|---|---|---|---|
| JPG | Photographs | No | Small files, universal support; lossy |
| PNG | Logos, screenshots, graphics | Yes | Lossless and crisp; larger for photos |
| WebP | Web images | Yes | ~25–35% smaller than JPG/PNG; widely supported |
| AVIF | Web images (smallest) | Yes | Best compression; slower to create; newer |
| HEIC | iPhone photos | Yes | Great compression, but limited support — usually converted to JPG |
| ICO | Website favicons | Yes | Holds several icon sizes in one file |
When to use each format
JPG — the everyday photo format
JPG (also written JPEG) is the default for photographs. It compresses colourful, detailed images into small files that open anywhere. The trade-off is that it's lossy — it discards some detail to save space — and it can't store transparency. For sharing photos by email or message, JPG is almost always the right choice.
PNG — sharp graphics and transparency
PNG is lossless, so it keeps every pixel exactly. That makes it ideal for logos, icons, screenshots, and anything with text or sharp edges — and it's the go-to when you need a transparent background. The downside is bigger files for full photographs.
WebP — the modern all-rounder
WebP does what JPG and PNG do, but with smaller files — typically 25–35% smaller at the same quality — and it supports transparency. It's now supported by every major browser, which makes it excellent for websites where speed matters.
AVIF — the smallest files
AVIF is the newest format here and usually produces the smallest files of all, even beating WebP, while supporting transparency and a wider range of colour. It takes a little longer to create and isn't supported by some older software, so it's best for modern websites.
HEIC — the iPhone format
HEIC is what iPhones use to store photos, and it's very space-efficient. The catch is compatibility: many websites, apps, and Windows PCs can't open HEIC files. The usual fix is to convert HEIC to JPG (or PNG) so the photo works everywhere. Our converter does this on your device, so your photos stay private.
ICO — website favicons
ICO is the format for the little icon in a browser tab — the favicon. An ICO file can hold several sizes at once, so the browser always has a crisp version. To make one, convert a square PNG to ICO and the converter builds a multi-size file for you.
Lossy vs lossless — what it means for quality
Lossless formats (PNG, and lossless WebP) preserve the image perfectly. Lossy formats (JPG, and lossy WebP/AVIF) throw away some detail to shrink the file — at high quality the loss is usually invisible, but repeatedly re-saving a lossy image can slowly degrade it. When quality matters and file size doesn't, choose a lossless format; when you need small files, a lossy format with a high quality setting is the sweet spot.
Frequently asked questions
What is the best image format for photos?
For sharing and compatibility, JPG is the standard. For websites, WebP or AVIF give the same quality at a smaller size.
JPG or PNG — which is better?
Use JPG for photographs and PNG for logos, screenshots, or anything needing transparency or crisp edges.
How do I convert a HEIC photo from my iPhone to JPG?
Open the converter, drop in the .heic file, choose JPG, and download — all in your browser, nothing uploaded.
Does converting an image reduce its quality?
Converting to PNG (lossless) doesn't. Converting to JPG/WebP/AVIF can, but at high quality the difference is usually invisible — and you control it with the quality slider.
How do I make a favicon for my website?
Convert a square PNG to ICO. The converter builds a multi-size .ico (16–256px) ready to use as a favicon.
More guides
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