Export the entire contact list from my iPhone to excel or csv on windows?

For exporting export the entire contact list from iPhone, CSV is usually better than Excel if your goal is compatibility.

CSV is a plain-text format that can be opened by Excel, Google Sheets, Numbers, Outlook, Gmail, and many contact management tools. It is lightweight, easy to import/export, and safer for moving contacts between platforms. The downside is that CSV may not preserve complex contact fields very well, such as multiple phone labels, contact photos, birthdays, notes, or groups.

Excel format (.xlsx) is better if you mainly want to view, edit, sort, or clean up contacts on a computer. It keeps columns neat and is easier to manage manually. However, it is not always the best format for importing contacts back into iPhone, Gmail, Outlook, or Android because some apps prefer CSV or vCard.

For iPhone contacts, the best format is actually vCard/VCF if you want a full backup or plan to import the contacts back to another phone. VCF is designed for contacts and can preserve more details than CSV.

Simple recommendation:

Use VCF for backup or phone-to-phone transfer. Use CSV if you want to open and manage contacts in Excel or Google Sheets. Use Excel only if your main purpose is editing and organizing the contact list manually.