There are three basic types of PDF files, but not all of them are searchable.
- Text-based or “true” PDFs are created from a word processor like Apple Pages or Microsoft Word. These are searchable.
- Image-based PDFs contain pages that are actually screenshots or images created from a scanner. Though the pages might contain text, the text is actually part of the image and thus is not searchable. A simple test is to try to select the text; if it can't be selected, chances are the file is not searchable. If you happen to have an image-based PDF, you will need the help of a third-party program to make it searchable. See the next type.
- OCR’d or “made-searchable” PDFs: Image-based PDFs that have been processed by a special Optical Character Recognition program to include an invisible, searchable text layer. These PDFs should still be searchable in GoodNotes. However, if re-exported from the app, the OCR layers might be stripped off, making the resultant PDFs not searchable. Unfortunately, this is due to how the original PDFs are encoded and there's little we can do here.
If you can't search an imported PDF that should be searchable, tap the Gear icon in the top-right corner of the Library view > Settings > Search Indexing, and make sure the option is enabled.
If you still have search issues with the file, please send it to us for a look.