Open an export before leaving an app
An export is a new file with its own limits.
An export is a new file with its own limits. Open it outside the original app before treating it as a dependable way to leave that service.
Choose an export format suited to what you need to preserve. A PDF may retain a readable layout while losing editing features. A spreadsheet or text export may retain data but omit comments, attachments or relationships. Read the application's documentation for the particular export rather than assuming one button includes everything.
Test a representative sample
Use a document with the features that matter to you: images, tables, notes or linked files. Save the export to a clearly named folder and open it in another suitable program. Compare it with the original, including the beginning, middle and end. Check dates and special characters where those affect meaning.
Write down what did not transfer. Decide whether you need a second format or a separate copy of attachments. Keep sensitive material in an appropriate location and avoid uploading it to an unfamiliar converter just to see whether it opens.
Do this before closing the account or removing the app. An accessible file is more useful than an export archive that requires the unavailable service to interpret it. Keep the original until you have checked enough of the result to make an informed decision.