Open the picture on your device
Select Print or Share
Choose Save as PDF or Print to PDF
Select the destination folder
Save the file
On Windows, open the image, press Ctrl+P, choose Microsoft Print to PDF, then save
On Mac, open the image in Preview, go to File, then Export as PDF
On iPhone, open the photo, tap Share, tap Print, zoom in on the preview, then save as PDF
On Android, open the image, tap Share or Print, choose Save as PDF, then save
Use an online image-to-PDF converter if needed
Combine multiple pictures into one PDF by selecting all images before saving