How to convert a photo to JPG for an online form (HEIC, PNG, WebP)
Why forms ask for JPG, how to get a JPG from a PNG or WebP image, and how to stop an iPhone from saving photos as HEIC.
Why forms ask for JPG
JPG (also written JPEG, with the extension .jpg or .jpeg) is the most widely accepted format for photos, and many forms accept nothing else. Photos can also arrive as PNG (screenshots, edited images), WebP (images saved from websites) or HEIC (iPhone camera). If a form rejects your file, check its extension first.
PNG and WebP to JPG
Open the image in PhotoSize; it accepts JPG, PNG and WebP. Set the size and KB limit from your form and download. Photos are always saved as JPG, so the downloaded file is ready for a form that asks for .jpg.
Transparent PNGs
JPG has no transparency, so any transparent areas need a colour. PhotoSize fills them, and any empty edges, with the background you choose: white, light blue or light grey. This only fills empty space; it doesn’t remove a background that is already in the photo.
HEIC from an iPhone
PhotoSize can’t open HEIC files yet. To make future photos save as JPG, go to Settings → Camera → Formats and choose Most Compatible, then take the photo again. For a photo you already have, a screenshot of it gives a PNG that PhotoSize can open; it has the screen’s resolution, which is usually enough for form-sized photos.
Signatures
In signature mode the default is also JPG. If the form accepts PNG, you can tick Save as PNG, which keeps the edges of the ink crisp. Only choose PNG if your form says it is allowed.
Check the extension
After downloading, check that the file name ends in .jpg. Renaming a file from .png or .heic to .jpg does not convert it, and some forms detect this and reject the file. Always make a real JPG with a converter such as this one.
Questions
How do I convert a PNG to JPG for a form?
Open the PNG in PhotoSize, enter your form’s size and KB limit, and download; photos are always saved as JPG. Transparent areas are filled with white or the colour you choose.
How do I stop my iPhone from saving photos as HEIC?
Go to Settings → Camera → Formats and choose Most Compatible. New photos are then saved as JPG, which forms and PhotoSize accept.
Can I just rename a .heic or .png file to .jpg?
No, renaming changes only the name, not the format inside the file. Many forms check the real format, so convert it properly instead.
Updated 2026-11-06