HEIC, WEBP, and AVIF Explained: A Guide to Modern Image Formats

JPG and PNG dominated image formats for decades because there was little competition, not because they were the best possible solution to every problem. HEIC, WEBP, and AVIF are newer answers to the same core question — how do you store an image with the smallest possible file size for a given level of quality — and each one has quietly become the default somewhere you probably already use. Here's what's actually different about them, and when converting between formats is worth doing.

HEIC: Apple's answer to smaller photo files

HEIC (High Efficiency Image Container) became the default photo format on iPhones starting with iOS 11, and it earns that "high efficiency" name honestly — it produces meaningfully smaller files than JPG at a comparable visual quality, which matters enormously given how many photos a phone camera generates in a single day. The catch is that HEIC support outside Apple's own ecosystem has been slower to arrive. Recent versions of Windows, many browsers, and a lot of everyday software either don't recognize it at all or need an extra codec installed first, which is why an emailed iPhone photo sometimes shows up as an unreadable file on someone else's computer. HEIC to JPG solves that instantly by converting to the format virtually everything can open.

WEBP: Google's format built specifically for the web

WEBP was designed from the ground up to solve a website's specific image problem: pages load faster when images are smaller, and WEBP typically beats JPG and PNG at that job while still supporting both lossy compression (like JPG) and lossless compression with transparency (like PNG) in one format. That flexibility is why WEBP has become the go-to recommendation for web performance audits. Browser support is now very broad across all major browsers, which is a big part of why converting existing image libraries to WEBP is one of the more effective single changes for a slow-loading website. JPG to WEBP and the broader image converter handle that conversion directly, including batches of many images at once.

AVIF: the newest, and often the smallest

AVIF is the newest of the three, built on the AV1 video codec's compression technology, and it frequently produces even smaller files than WEBP at an equivalent visual quality. Its main limitation is simply age — AVIF hasn't been around as long, so support across older software, some content platforms, and various upload systems still lags behind the more established formats. That's usually a temporary gap that closes as adoption grows, but for now, converting an AVIF file to a more universally recognized format is sometimes the pragmatic choice for compatibility with a specific destination.

So which format should you actually use?

For photos you're taking and keeping on your own device, whatever your device defaults to (often HEIC on an iPhone) is fine, since the efficiency gains are real. For sharing a photo broadly, or uploading somewhere you're not sure will support a newer format, converting to JPG remains the safest universal choice. For images on a website you control, WEBP is the well-supported sweet spot between file size and compatibility today, with AVIF as an option worth testing if your specific platform and audience support it. The deciding factor is almost always the destination, not the source — which is why having a fast way to convert between all of them matters more than picking one format to use everywhere.

The image converter handles every combination of PNG, JPG, WEBP, AVIF, HEIC, GIF, BMP, TIFF, SVG, and ICO in one place, entirely in your browser. If you're specifically dealing with iPhone photos, HEIC to JPG is the fastest path to compatibility — see our guide to why HEIC photos won't open for more on that specific problem. And if you're deciding between JPG, PNG, and WEBP specifically for a photo you already have, the JPG vs PNG vs WEBP breakdown covers that comparison in more depth.