1. Convert
Open HEIC to JPG and add one or many photos. They are converted on your device.
2. Shrink if needed
If a form has a size limit, run the JPGs through Compress image.
3. Need a PDF instead?
After converting, add the JPGs to JPG to PDF to make a single document.
Questions
Why can't some browsers open HEIC?
Support varies between browsers. The tool tells you if your browser can't decode the file.
Related: Turn photos into one PDF · Make images smaller for the web · Resize many images at once