How to Convert HEIC to JPG and Resize Photos in Bulk on a Mac
iPhones save photos as HEIC. The files are small and good-looking, but many websites, forms, Windows PCs and older apps still expect JPG, and a dozen full-size photos are too heavy for an email. You can fix both on your Mac without uploading anything to a converter website.
The short answer: select the photos in the Finder, right-click, choose Quick Actions › Convert Image, then pick JPEG and a size. That covers the simple cases. If you want an exact size (say 2,048 pixels on the long side), a quality setting, and an undo, Folia Files puts Resize… and Convert To in the right-click menu, for one photo or several hundred.
What your Mac can already do
The Finder: Quick Actions › Convert Image
- Select the HEIC photos in a Finder window.
- Right-click (or Control-click) one of them and choose Quick Actions › Convert Image.
- Choose a Format (JPEG, PNG or HEIF) and an Image Size, and decide whether to keep Preserve Metadata (the date taken, the camera, the location).
- Click Convert to JPEG.
The JPEG files appear next to the HEIC files, which stay as they are. It is built in and quick. The limits: the sizes are a few presets rather than an exact number of pixels, and there is no quality setting to make the files lighter.
Preview: resizing, but on the originals
Select the photos and press ⌘O: they open together in one Preview window. Select every thumbnail in the sidebar (⌘A), then choose Tools › Adjust Size… to resize them all at once. With several images selected, Preview's File menu can also export them all to another format.
The catch: Adjust Size changes the files you opened, not copies of them. If you want to keep the full-size photos, duplicate the folder first.
Terminal: sips
macOS comes with sips, a command-line image tool. In Terminal, go to the folder with cd, then:
mkdir jpg
for f in *.HEIC; do sips -s format jpeg -s formatOptions 85 "$f" --out "jpg/${f%.*}.jpg"; done
Every .HEIC file becomes a JPEG at 85% quality in a new jpg folder. To shrink pictures so their long side is 2,048 pixels at most:
sips -Z 2048 *.jpg
Careful: without --out, sips -Z overwrites the pictures themselves, and nothing in Terminal can undo it. The patterns are also case-sensitive: *.HEIC skips a file named photo.heic.
Convert and resize in bulk from the right-click menu
Folia Files is a file manager for the Mac. In any of its views, select one or more pictures and right-click: the context menu has an Image submenu, or Images (3) when three are selected. It appears when the selection holds only pictures, with no folders or videos mixed in.
Resize…: a percentage, a long side or an exact size
Resize… opens a small sheet that shows the size of the first picture and what it will become:
- Size: 25%, 50% or 75%; Long side: 1,024 px, 2,048 px or 4,096 px; or Custom Size, a width and a height. With Scale proportionally ticked, each picture fits inside that box; unticked, every picture gets exactly that size, even if it is stretched.
- Format: Same as Original, JPEG, PNG or HEIC. So one pass can shrink HEIC photos and turn them into JPGs.
- Quality: a slider from 30 to 100%, shown when the result is a JPEG or a HEIC. The first time, it is set to 85%.
The long-side choices never enlarge a picture. With Same as Original, a photo that is already small enough is left alone, and Folia Files tells you so. Each result is named after its original with what was done, for example IMG_4027 (2048 px).jpg, and the sheet remembers your last choice.
Convert To: JPEG, PNG, HEIC or TIFF
Convert To turns every selected picture into JPEG, PNG, HEIC or TIFF, at full size. The new file keeps the original's name with its new extension, so IMG_4027.HEIC gives IMG_4027.jpg. If that name is already taken, a number is added (IMG_4027 2.jpg). A format that all the selected pictures already have is greyed out; in a mixed selection, the pictures already in that format are skipped.
Both commands keep the date taken, the camera details and the location, and save the picture the right way up. A picture with transparency gets a white background when it becomes a JPEG or a HEIC, since those formats have no transparency.
The originals stay, and ⌘Z takes it all back
Whatever you choose, Folia Files writes new files next to the originals and never writes over anything. Each run is one operation in Operations (in the toolbar), with its progress and a way to cancel, and the new files are selected when it ends. It is also one entry in the history: press ⌘Z right after, or click Undo next to it in Operations › History later, and the new files go to the Trash.
The same submenu has Rotate Left, Rotate Right, Flip Horizontal and Remove Location and Metadata, useful before posting photos online. Each one makes a copy too. On videos, a Video submenu converts to MP4 (H.264 or HEVC), reduces to 1080p or 720p, or extracts the audio.
The menu is in both editions, the website one and the Mac App Store one. In the App Store edition, Folia Files may first ask you to open the folder once (a standard Open panel), so it is allowed to write next to your photos.
Going further: Batch Actions and drop-on tiles
More Options…, at the bottom of the submenu, opens Batch Actions with the same pictures. There you chain more steps, such as Crop, Watermark or Add Margins, with the resize and the format, keep the chain with Save as Preset…, and choose where the results go: by default, a Processed subfolder next to the originals.
If you shrink photos every week, keep the Quick Actions module at hand (not to be confused with the Finder's Quick Actions): in the right sidebar, from its Modules button, or in a pane of its own, by dragging New Pane from the toolbar. Its Convert to JPEG tile (85% quality) and Shrink Images tile (long side 2,048 px at most) work on the photos you drop on them, or on the current selection when you click.
You can also move the Image and Video entry higher in the menu, or tuck it into More, from Settings › Context Menu; here is how to customize the right-click menu.
Which method to use
- A few photos, nothing to set: the Finder's Convert Image.
- A script you already know:
sips, always with--outso the originals stay. - An exact size and quality in one pass, with an undo: Folia Files' Resize… and Convert To.
To check the result, a list that shows each picture's pixel size helps: see how to see image dimensions in a folder list. And if you would rather not get HEIC files at all, the iPhone can take JPEG photos: in its Camera settings, under Formats, choose Most Compatible.
