Isn't converting HEIC to JPG a double loss?

Technically yes, a second round of lossy compression is added. In practice, though, at a sensible JPG quality setting the visible effect of that second round is negligible on most photographs. The real risk lies in saving at a low quality setting or re-saving the same file over and over. A single high-quality HEIC-to-JPG conversion generally gives a perfectly acceptable result for everyday use.

If I don't need transparency, does PNG have any advantage at all?

It has one: it stops generation loss. If you are going to put a photo through an editing process spread across several sessions, keeping the intermediate saves as PNG prevents compression artefacts from accumulating with every save. But if you are doing a one-off conversion and using the file as-is, that advantage never comes into play. In that case PNG leaves you with nothing but a much larger file.

What format should I batch-convert my iPhone photos to?

For batch conversions, JPG or WEBP is almost always the right answer. The goal is usually to solve HEIC's compatibility problem on Windows and the web, and both formats handle that at reasonable file sizes. Converting hundreds of photos to PNG multiplies your storage requirements and delivers no visible quality gain in return, because the loss already happened at capture time.

Which one for HEIC files that are documents or screenshots?

PNG is markedly better for that kind of content. Document photos, signage, screenshots and whiteboard shots contain sharp edges and large flat colour areas. JPG produces halos around text edges and general mush on this kind of content, whereas PNG gives a clean result — and because its lossless compression works efficiently here, the file does not balloon the way it does with photographs.

HEIC Photos: Does PNG or JPG Make More Sense?

Start by asking the right question

When you convert a HEIC file, the answer to "PNG or JPG?" has less to do with the photo's quality than with what you plan to do with the file. Because here is the critical fact: HEIC is already a lossy format. Some detail was permanently discarded the moment the photo was taken, and no target format will bring it back.

That largely demolishes the "PNG is lossless, therefore higher quality" argument. PNG is lossless, but it does not give you a lossless photograph; it puts a lossy photograph into a lossless container.

So the real question is: are you going to edit this file, or use it as-is?

On quality: the gap is smaller than you think

Going from HEIC to PNG introduces no new loss. Going from HEIC to JPG adds a second round of lossy compression. On paper, PNG wins.

In practice, at a sensible JPG quality setting, the visible effect of that second round is indistinguishable by eye on most photographs. The difference can surface in wide gradient areas like a sky, or under heavy zoom. At normal viewing distance the two outputs are impossible to tell apart.

The conclusion: PNG's quality advantage is technically real but practically small. Its size cost, on the other hand, is not small at all.

On file size: the gap is enormous

On photographic content PNG loses decisively. Sensor noise and texture mean almost every pixel differs from its neighbour, so PNG's pattern-based lossless compression finds no repetition to pack. The PNG version of a photo lands at a file size far above the JPG version.

But that generalisation holds only for photographs. Change the content and the balance changes with it:

Photographic content: JPG is markedly more efficient. Landscapes, portraits, food, product shots — all in this category.

Graphic and text content: The gap closes and can even reverse. Document photos, screenshots, signage and slide captures contain large flat colour areas. PNG packs those efficiently; JPG produces halos on sharp edges and mush on text.

Transparency: there is no comparison here

The JPG format defines no alpha-channel component in its structure. Each pixel carries colour information only. That is not a software shortcoming; it is a design decision baked into the format.

PNG, by contrast, can store 256 distinct levels of opacity per pixel. That allows smooth transitions between fully visible and fully invisible — the edges of a cut-out object look smooth rather than jagged against any background.

So if you have a HEIC photo whose background you intend to remove, the comparison ends right there. JPG is not an option; your target format has to be PNG. The HEIC to PNG converter is the first step of that workflow.

Decisions by scenario

Opening the photo on Windows or uploading it to a form: JPG. The goal is purely compatibility; there is no reason to pay a size penalty.

Publishing the photo on a website: JPG or WEBP. PNG weighs the page down for nothing, and visitors will see no difference.

Removing the background to produce a product image: PNG. Transparency is mandatory; there is no alternative.

Doing multi-stage editing: PNG. It reduces generation loss on intermediate saves to zero. You export the final version as JPG or WEBP at the very end.

Photos of documents, screenshots, signage: PNG. Text and sharp edges stay clean and the size stays reasonable.

Converting a bulk photo archive: JPG or WEBP. Converting hundreds of files to PNG multiplies your disk cost and delivers no visible benefit at all.

Sending as an email attachment: JPG. You get under size limits, and the recipient notices nothing.

The mistake people keep making

The most common misconception is "PNG is lossless, so it's always better," which leads people to convert their entire HEIC archive to PNG. The single concrete outcome is using several times as much disk to store the same images. The loss happened at capture; PNG does not compensate for it, it merely freezes the current state.

The second mistake is converting to PNG and then back to JPG in an attempt to "clean up" the image. That loop fixes nothing and adds one more round of lossy compression at the final step.

In summary

If you need transparency, PNG is the only option and there is no comparison to make. If you are doing multi-stage editing, PNG is a sensible working format. In every other scenario — sharing, publishing, archiving, compatibility — JPG is clearly the better decision. PNG's technical quality advantage is real but small; its size cost is real and large. Make the call on that balance.