Convert HEIC to WebP

Most people escaping HEIC go to JPG, and for a photograph headed into an email or a document that is the right answer — it opens on absolutely everything, including software that has not been updated this decade.

For anything going on the web it is leaving a third of the file size on the table. WebP reaches the same visible quality in roughly 25 to 35 per cent fewer bytes, which is the kind of margin that shows up in a page speed score and on a mobile connection. It also keeps transparency and handles flat colour without the smearing JPG produces around hard edges, so one format covers photographs and graphics alike.

HEIC and WebP are closer relatives than either is to JPG. Both came out of video compression research, both use techniques JPEG predates by twenty years, and both are lossy in similar ways. That matters in practice: WebP is not struggling against artefacts the source introduced, the way JPG sometimes does when re-compressing something already compressed.

The result is that the default quality setting is genuinely sufficient here. What is worth raising it for is a photograph that will be cropped hard or printed, where you are effectively enlarging part of the image and any softness enlarges with it.

Nobody has one HEIC. They have four hundred, because the phone has been producing them since iOS 11 and the format only becomes a problem when the photographs need to go somewhere else.

Drop up to a hundred at a time; each converts independently with its own progress, and once several have finished a single button offers them all as a ZIP. Nothing queues behind anyone else because there is no shared server — the work happens on your own machine. Through a site that uploads, the same job is a hundred uploads, a wait, and usually a daily cap designed to sell you a subscription.

An iPhone photograph is not only an image. It usually holds the exact coordinates where it was taken, the date and time, the device model, and often the camera settings. That travels with the HEIC file wherever it goes.

The WebP produced here does not include any of it. For photographs destined for a website, a forum or a marketplace listing, that is almost certainly what you want — published images have leaked home addresses more than once. If you specifically need the metadata preserved, this conversion is the wrong tool, and you should know that before rather than after.

WebP has a lossless mode, and for a photograph out of a phone it is the wrong choice: it faithfully preserves an image that was already compressed, at several times the size.

It earns its place for screenshots and graphics, which a phone can also produce as HEIC. If the source is a picture of a screen rather than a picture of the world, lossless is worth trying.

A Live Photo is a still with a short video attached. What converts is the still, because the WebP produced here holds one frame — the video stays behind in the original file.

A burst behaves as what it is, a set of separate stills, so dropping the whole set converts each one. Nothing is quietly discarded except the motion, and only where there was motion to discard.

In browsers, effectively everywhere, and for years. Outside them it is uneven: some older image viewers, a few editors, certain systems that process attachments, and upload forms that judge by extension alone.

Which is why the division is worth stating plainly. WebP for your own pages; JPG for anything going to a person whose software you do not know.

A HEIC is already efficient, so the WebP will not be dramatically smaller and may even be slightly larger. The comparison that matters is against JPG, not against the HEIC you started with.

Against a JPG at the same visible quality, expect 25 to 35 per cent fewer bytes. That is the margin this conversion exists for, and it is why the destination — a web page — decides whether the exercise makes sense at all.

This reads HEIC and HEIF and writes WebP, JPG, PNG and the rest. The reverse does not exist on this site, and that is a licence question rather than a missing feature: the encoder required comes on terms that do not fit the ones this site holds its dependencies to.

In practice it should not matter. HEIC earns its place when an Apple device is saving storage, and that is settled in the camera settings rather than by converting files afterwards.