How do I convert HEIC photos to JPEG before uploading?

HEIC is fully supported, so converting is a preference rather than a requirement. The simplest options are to switch your iPhone camera to JPEG mode, or to export as JPEG from Photos on Mac or Lightroom.

iPhone — switch to JPEG mode (best for future shoots)

Settings → Camera → Formats → choose Most Compatible instead of High Efficiency. From that point forward, your iPhone captures JPEG instead of HEIC.

Mac — Photos app

Select your HEIC photos, go to File → Export → Export Photos, and choose JPEG as the format. The exported JPEGs are ready to upload.

Lightroom Mobile or Classic

Import your HEIC files, then export with JPEG format selected.

Once converted, upload the JPEGs as you normally would.