Manatee

How to convert photos to HEIC to save space on a Mac

· 6 min read

HEIC stores a photo in roughly half the space of a JPEG at similar quality, so converting a pile of JPEG or PNG images to HEIC is one of the simplest ways to reclaim disk space on a Mac. The fastest way is to drop the photos on a converter, choose HEIC as the target, and save; keep the originals until you are happy with the results. Preview can export single images to HEIC too.

How HEIC saves space

HEIC is a High Efficiency Image File, a container built on the HEVC compression standard. HEVC is a much newer and smarter compressor than the one JPEG uses, so it can represent the same photograph with noticeably fewer bytes at the same visual quality. In practice a HEIC file is often about half the size of the equivalent JPEG, and the saving against a PNG photo is larger still, because PNG stores photographs losslessly and therefore inefficiently.

Macs running macOS 12 or later handle HEIC natively, on both Apple silicon and Intel, so a converted library opens and previews exactly as your current photos do. The space you free up is real: across thousands of images, halving the size of each adds up to gigabytes. The saving is most dramatic for the images that were wasteful to begin with, such as photos that were saved as PNG or exported at maximum JPEG quality, where the newer compression has the most slack to work with.

Why, and when, to convert to HEIC

The clear win is storage. If a folder of holiday photos or a working archive of screenshots is crowding your disk, converting to HEIC shrinks it without dropping to a visibly lower quality. It is a good fit for a personal library that lives on your Mac and Apple devices, where HEIC is understood everywhere.

The trade-off to weigh is compatibility. HEIC is not universally supported outside the Apple ecosystem; older Windows versions, some web upload forms, and various apps will not open it. So HEIC is excellent for photos you are storing, and less ideal for photos you are about to send to someone on an unknown device or post to a site that has not caught up. A sensible pattern is to keep your library in HEIC for the space saving, and export a JPEG copy on the occasions you need to share widely.

It also helps to be honest about which files are worth converting. Photographs, with their smooth gradients and fine texture, are where HEVC compression shines and where the space saving is largest. Flat graphics, logos, and screenshots full of sharp text see a smaller benefit and can even look slightly softer, so those are often better left as they are. Sort your candidates before a big conversion, and you spend the effort where it actually pays off.

Convert photos to HEIC on a Mac

Manatee is built for exactly this kind of batch job, and it can take a whole folder in one pass:

  1. Open Manatee and choose Convert, or drag the photos onto its menu bar icon.
  2. Pick HEIC as the target.
  3. Drop in the files, or the folder that holds them. Each appears in the job list with progress.
  4. Each new HEIC is written alongside its original. Nothing you started with is changed.

Because Manatee always writes a new copy and never touches the source, you can convert first, confirm the HEIC versions look right and open where you need them, and only then decide whether to remove the originals. It all runs on your Mac, with no upload and no account.

For a single image, Preview works:

  1. Open the photo in Preview.
  2. Choose File, then Export.
  3. Set the Format to HEIC, holding the Option key first if it is not shown, and adjust the Quality slider.
  4. Click Save.

Preview is handy for one file at a time, but it becomes slow work for a large library, which is where converting a whole folder at once earns its keep.

The trade-offs worth knowing

HEIC compression is lossy, so converting a photo to HEIC is a re-encode, not a lossless repackage. Converting a JPEG to HEIC means the image is compressed a second time, and while the quality drop at a sensible setting is small and hard to see, it is not zero. Converting a PNG to HEIC loses a little more, since you are moving from lossless to lossy, but that is usually a fair exchange for the large size reduction on a photo. The practical rule is to convert once, from the best source you have, rather than re-encoding the same image repeatedly.

Keep your originals until you are certain. Data thrown away in compression does not come back, so the safe order is convert, verify, and only then reclaim the space. And remember the still-image nature of the format: converting individual photos to HEIC is about storage, not about preserving Live Photo motion or depth, which live in the original files from your phone.

Questions

How much space will I actually save?

For JPEG photos, expect roughly half the size at similar quality; against PNG photos the saving is usually much larger. Across a big library that easily adds up to gigabytes.

Will converting to HEIC reduce quality?

Slightly. HEIC is lossy, so converting is a re-encode. At a reasonable quality setting the difference is hard to notice, but you should convert from the original rather than re-compressing the same image again and again.

Will HEIC files open on other devices?

On Apple devices and recent software, yes. Older Windows systems, some websites, and various apps may not open HEIC, so keep or export a JPEG copy when you need to share with an unknown device.

Is it safe to delete the originals after converting?

Only after you have checked the HEIC versions look right and open where you need them. HEIC is lossy, so the discarded detail cannot be recovered. Convert, verify, then reclaim the space.