Why Facebook rejects iPhone photos
Facebook's upload system does not accept HEIC — the default photo format on iPhones since iOS 11. When you try to attach a photo directly from your iPhone camera roll through a desktop browser, the upload typically fails silently or shows a generic error. On mobile, the Facebook app handles some HEIC conversion internally, but the desktop web interface does not.
The second common cause is file size. Facebook accepts timeline photos up to 15 MB and Marketplace listing photos up to 10 MB. iPhone photos in ProRAW or high-resolution mode can exceed 20 MB easily. Night-mode shots and panoramas are also frequently oversized.
How Facebook compresses your photos
Facebook re-encodes every photo you upload to its own JPEG regardless of what you send. This is why photos sometimes look softer on Facebook than they did on your phone. The platform downsamples to a maximum of 2048 px on the longest edge and applies its own compression.
Pre-converting your HEIC to JPEG at quality 85 before uploading gives Facebook's encoder a cleaner, lower-noise starting file. The result after Facebook's re-encode tends to look sharper than when you upload a large raw file that Facebook has to crush more aggressively.
Facebook Marketplace photo requirements
Marketplace listings have a tighter 10 MB limit per photo and the same HEIC rejection. For sellers listing multiple items — furniture, clothing, cars — batch-converting a folder of phone photos saves time. Drop your folder above, all photos convert in parallel, then download them individually or all at once as a ZIP — free either way.
Related: HEIC to JPG · Compress for Instagram · Shopify product image too large