WebP: small files, modern web
WebP is Google’s image format designed for the web. Its big advantage is efficiency: at the same perceived quality, a WebP file is usually noticeably smaller than the equivalent JPG, and far smaller than PNG. That means faster-loading pages, less bandwidth, and better Core Web Vitals if you publish images online. Your iPhone’s HEIC photos already use efficient HEVC compression, but HEIC barely works on the web — converting to WebP keeps files small and makes them open in every browser, so it’s the natural move when the destination is a website, a blog, or an app.
How much smaller is WebP?
The exact saving depends on the image, but at a comparable visual quality WebP files are commonly around 25–35% smaller than JPG and a fraction of the size of a lossless PNG. WebP also supports a true alpha (transparency) channel, which JPG lacks, so transparent areas survive the conversion instead of being flattened onto white. The newer AVIF format can go even smaller, but WebP currently has the wider, more reliable support across browsers and tools — which usually makes it the safer default for a real website today.
WebP vs JPG vs PNG vs AVIF — a quick comparison
| Format | Typical size | Transparency | Support | Best for |
|---|---|---|---|---|
| WebP | Smallest of the mainstream three | Yes | All modern browsers | Website & app images |
| JPG | Small | No | Universal (everything) | Sharing, email, uploads |
| PNG | Largest | Yes | Universal | Lossless, graphics, text |
| AVIF | Often smallest of all | Yes | Newer browsers only | Cutting-edge web, with fallback |
When WebP is the right choice (and when it isn’t)
Choose WebP when you’re putting images on the web and want them to load quickly. Choose JPG when you’re emailing photos or sending them to someone whose software you can’t predict, since JPG is the most universally compatible format. Choose PNG when you need guaranteed-lossless quality or transparency. SnapHEIC gives you all four — including PDF — from the same private, in-browser engine.
Color and quality — the honest version
HEIC can hold 10-bit color in the wide Display P3 gamut. Like every browser-based converter, SnapHEIC maps that down to standard 8-bit sRGB when it decodes the photo, so a WebP from any in-browser tool won’t carry a wider color range than a JPG would. That’s rarely a problem in practice: sRGB is exactly what browsers, apps and the web expect, so your images look correct everywhere you publish them. WebP’s real win is size — same-looking photo, fewer kilobytes.
Converted privately, on your device
Like every SnapHEIC tool, HEIC → WebP runs entirely in your browser. Your photos are decoded with a WebAssembly build of the HEIC codec, re-encoded as WebP, and returned to you as downloads — no upload, no account, no watermark, and no cap on the number of files. You can verify the “no upload” claim yourself: open your browser’s DevTools → Network tab while converting, or just turn on airplane mode and watch it keep working. The conversion also drops EXIF metadata such as GPS coordinates, so the images you publish don’t expose your location.
Tuning quality and size
Use the quality slider to find the right balance for your use case. Around 80–90% is usually indistinguishable from the original for photos while keeping files small; push toward 100% for near-lossless output when detail matters. Because you can convert a whole batch at once and download everything as a ZIP, preparing a folder of web-ready images takes seconds.