Which compresses better, HEIC or WEBP?

Both are efficient formats of their generation, and the gap between them varies with the content. Because HEIC is built on the HEVC video codec, it is particularly strong on complex photographic material. WEBP offers a clear advantage over JPG, but its margin against HEIC shifts from photo to photo — there is no clean one-way superiority. In practice, when choosing between these two, support matters far more than compression efficiency.

Is WEBP's lossless mode an advantage over HEIC?

For certain jobs, yes. WEBP can operate both lossily and losslessly; in lossless mode no pixel information is discarded, which is valuable for editing workflows and sharp-edged graphics. HEIC, in practice, is used as a lossy format. But lossless WEBP produces very large files on photographs, so this advantage is meaningful for graphics and text-heavy images, not for holiday snaps.

Why does the iPhone use HEIC while the web uses WEBP?

The two came out of different ecosystems with different needs. Apple wanted to use device storage efficiently and made HEIC the default on phones that already had hardware HEVC support. WEBP was developed by Google to speed up web pages and was built around browser support. The result is that HEIC dominates on the device and WEBP dominates on the web, which is exactly why a photo leaving your phone has to change format on its way to the web.

Do both support transparency?

WEBP supports an alpha channel in both its lossy and lossless modes, so you can produce images with transparent backgrounds. HEIC can technically carry alpha too, but that capability is not used in the practical phone-photography workflow and the number of programs supporting it is limited. If your work requires transparency, WEBP is by far the safer choice.

HEIC and WEBP: How Two Modern Formats Differ

Two formats, two different problems

On the surface HEIC and WEBP look like they do similar things: both are modern, both beat JPG on efficiency, both came out of the 2010s. But the questions that brought them into existence are quite different.

The question HEIC set out to answer was: "The user has thousands of photos on their phone — how do I store them without filling up the storage?" WEBP's question was: "Why is this web page loading so slowly and how do I shrink its images?"

That distinction explains where each format dominates today, and why you find yourself having to convert between them.

How HEIC works

HEIC is the HEVC (H.265) video codec adapted to still images. Video compression had for years enjoyed more advanced techniques than photo compression; HEIC brought that accumulated work to the single frame.

The result is impressive. HEIC can store the same perceived quality with markedly less data than JPG. That is precisely why Apple made it the iPhone default — and phones already had hardware HEVC support, so encoding and decoding were fast and battery-friendly.

HEIC is a lossy format. The moment the photo is taken, information the human visual system is insensitive to is discarded and never comes back. That is not a flaw but a design choice; the format's efficiency comes from exactly this.

HEIC is also a container: a single file can carry multiple images, a depth map, edit history and other extra data. That is the mechanism behind Live Photo.

How WEBP works

WEBP was developed by Google for web performance. Its lossy mode is built on techniques from the VP8 video codec; its lossless mode takes an entirely different approach, using pattern prediction and entropy coding.

WEBP's most defining characteristic is its versatility: one format carrying four capabilities at once.

Lossy compression. For photographs, it produces files roughly a quarter to a third smaller than JPG. This is WEBP's best-known trait.

Lossless compression. No pixel information is discarded. It serves as an alternative to PNG for graphics, logos and screenshots.

Transparency. It supports an alpha channel in both lossy and lossless modes. That means it can offer PNG's transparency at a cost closer to JPG's file size — a significant practical advantage.

Animation. It can store moving content and is used as the modern alternative to GIF.

Support: this is where they really diverge

The technical specifications are interesting, but in daily life what separates the two formats is where they open.

HEIC's support is narrow. It works seamlessly inside the Apple ecosystem. Windows demands an extra codec installation. Web browsers generally do not display it directly. Plenty of web forms, corporate upload systems and desktop editors do not recognise a HEIC file. This is very nearly the only reason people go looking for a way to convert out of HEIC.

WEBP's support is broad. On the browser side it has reached a level of ubiquity you could now call standard, and modern operating systems open it natively. Even so, do not assume it works everywhere: some older desktop programs, prepress tools and corporate systems may not accept WEBP.

So the real difference between the two lies not in the compression mathematics but in the ecosystem. HEIC is good inside the device; WEBP is good outside it.

What happens in the conversion

Moving from HEIC to lossy WEBP adds a second round of lossy compression. HEIC was already lossy, and WEBP's loss stacks on top. At a sensible quality setting the visible effect of that second round is indistinguishable under normal conditions, but mathematically the information loss is real.

Keep your expectations measured on the size front. Because HEIC is already very efficient, moving to WEBP brings no dramatic reduction; the file size can stay similar and on some photos grow slightly. WEBP's size advantage is against JPG, not against HEIC.

So why convert at all? Because converting HEIC to WEBP buys you compatibility: your file now opens in a browser, uploads to a form, publishes on a website. What you gain is not bytes but usability.

Where to keep which

On the phone: HEIC. It is the right choice for storage efficiency, and the device opens it without trouble.

On a website: WEBP. Browser support is broad and the file size advantage over JPG is clear.

In an archive: It depends. If long-term accessibility matters and you do not know what software you will use to open the archive years from now, formats with broader support are safer.

During editing: A lossless format. Lossless WEBP or PNG prevents generation loss on intermediate saves.

In summary

HEIC and WEBP are not rivals but two efficient formats designed for different ecosystems. HEIC is superior for on-device storage, WEBP for the web and general compatibility. Converting between them is done not for a quality or size gain but so you can actually use the file. Set your expectations accordingly and you will be happy with the result.