Some might suggest you download an app to convert a picture to a PDF on the iPhone, but the truth is you can do it for free without any apps.

How can I convert an image to PDF? Windows and macOS already offer integrated on-board tools with which you can convert images to PDF without installing additional software.

When it comes to converting file extensions on your iPhone, don't worry about downloading a third-party app when you can make the changes yourself.

From the Files app that comes with iOS, for example, you can convert images into PDF files by long pressing on them and choosing Create PDF from the menu that comes up.