A slightly more advanced, but still pretty quick and easy, without any programming:
- Download Postman (postman.com) or something like it.
- Set up a new GET request for: https://api.hubapi.com/crm/v3/properties/contacts
- In the Authorization tab, choose type: API Key.
Key:hapikeyValue: (Find your API key) - Hit Send and then copy the results.
- Convert the resulting JSON to CSV (Parabola is a super easy way to do this if the file is too big. Just set up a new flow with JSON file, set Top Level Keys to results. Actually, if you use Parabola, just do an API import and you can skip Postman altogether!)
