HEIC vs HEIF: what's the difference?
HEIC and HEIF are often used as if they were two names for one thing. They are closely related, but not the same, and the difference decides which files HEIC to PDF can turn into a PDF.
HEIF is the container
HEIF stands for High Efficiency Image File Format. It was standardised by MPEG as ISO/IEC 23008-12, and it describes a container: how a file packs together one or more images, their thumbnails, which way is up and other information. The container itself does not decide how the pixels are compressed. That is the job of a codec, and HEIF can carry images made with different codecs.
HEIC is HEIF with HEVC inside
HEIC is a HEIF file whose images are compressed with HEVC — High Efficiency Video Coding, also called H.265 — a codec first designed for video. Apple has used HEIC for iPhone photos since iOS 11, released in 2017, whenever the camera format is set to High Efficiency. HEVC needs fewer bytes than JPG for a photo of similar quality, which is why the format exists.
You will meet three extensions: .heic is the most common, and .heif and .hif are used too. The extension is only a label, though.
AVIF: the same container, a different codec
AVIF uses the HEIF container too, but its images are compressed with AV1 instead of HEVC. HEIC to PDF does not accept AVIF, and neither does any other app in the family. An AVIF file gets a card that says AVIF isn’t supported. Add HEIC or HEIF photos.
The app reads the file, not its name
When you tap Add HEIC photos, the app looks inside each file: is it a HEIF container, and is its main image coded with HEVC? That is what decides.
- .heic, .heif, .HEIC and .hif files with HEVC images open.
- A real HEIC that was renamed to .jpg opens too.
- A JPG, PNG or WebP image renamed to .heic is still a JPG, PNG or WebP inside. Its card says so and links to JPG to PDF, PNG to PDF or Image to PDF.
So for converting HEIF to PDF there is nothing to choose: a HEIF photo with HEVC images is a HEIC photo, whatever its extension.
One file, several images
Because HEIF is a container, one file can hold more than one picture:
- An image collection — several images in one file. Only its main image, which the file marks as the primary one, goes into the PDF.
- An image sequence — an animated .heics file. Its main still image goes in, as one page.
- An HDR photo from an iPhone carries an extra “gain map” image meant for HDR screens. It is not used; the standard photo goes in.
Live Photos
A Live Photo is two files: the HEIC is the still photo, and the moving part is a separate .MOV video. HEIC to PDF takes only images, so the still photo becomes a page and the video never goes into the PDF. If you add the .MOV by mistake, its card says This isn’t an image this app can read.
Where to go next
How to convert HEIC to PDF walks through the steps, and iPhone photos to PDF covers the camera setting and how to get the HEIC files off your phone.
Make your PDF in the browser → HEIC to PDF