HEIC and WebP: two modern formats with different homes
HEIC and WebP were both designed to beat JPG on compression, but they ended up in different places. HEIC is the default capture format on iPhones and is excellent for storing photos on the device, yet web browsers other than Safari do not display it. WebP, created by Google, is supported by every current browser but is rarely used by cameras. Converting HEIC to WebP takes your photo from the format that is best for your phone to the format that is best for the web.
Why it helps your website
Images are usually the heaviest part of a web page. Uploading full-size HEIC-to-JPG conversions can add several megabytes per photo, slowing down pages and hurting search rankings through Largest Contentful Paint. A WebP at quality 80 and sensible dimensions is often under 200 KB for a photo that fills a laptop screen. For the best result, combine conversion with resizing: very few layouts display images wider than 1600–2000 pixels.
How the conversion works
Each HEIC file is decoded by libheif, the reference HEIF library, compiled to WebAssembly and running in a background Web Worker. The image is rotated according to its metadata and then encoded with libwebp, Google’s own encoder, also as WebAssembly. Metadata such as GPS location is not copied into the WebP, which is a sensible default for images that will be published.
Typical savings
As a rough guide, a 12 MP iPhone photo of about 2 MB as HEIC becomes roughly 3–4 MB as a quality-90 JPG, but only 1.5–2.5 MB as a quality-80 WebP at full resolution. Resized to 2000 pixels wide, the same WebP usually drops to 250–400 KB, small enough for a fast-loading blog post or product page.
WebP or AVIF?
AVIF compresses even better than WebP, often 20% smaller again, but encoding is slower and some content management systems and image CDNs handle it less gracefully. WebP is the safe modern choice today. If you want to experiment, the image converter can produce AVIF from the same HEIC files.