Start with the exporter’s original file
Address books can hold several phone numbers, email addresses, postal addresses and labels for one person. A simple spreadsheet with one phone column cannot express that entire structure. Start with the original vCard or CSV export, not a screenshot or a spreadsheet that has already rounded identifiers or reformatted dates. Keep a separate copy before editing.
Contact Workbench reads supported vCard 2.1, 3.0 and 4.0 files. It decodes text, structured names and addresses, repeated properties and supported embedded media. The reader is bounded and does not claim to implement every extension. If an encoding or malformed structure is refused, obtain a fresh export from the source application instead of removing headers until the error disappears.
Choose a format for the receiving application
A general vCard 3 file is useful for a manual vCard import workflow, while a vCard 4 destination may accept newer value and parameter conventions. Neither format guarantees that a particular address book will retain every extension. Compare a small import containing a non-Latin name, two phone numbers, a labeled email and a postal address before importing the entire list.
The Google CSV profile uses template-style repeated columns. The English Outlook profile uses fixed email, phone and address slots. Both flatten parts of the contact structure and omit fields that have no supported destination mapping. Generic CSV is different: its JSON field columns are intended for inspection and data processing, not direct provider import. Read the profile’s change ledger instead of assuming that a successful download proves import fidelity.
Keep the review archive with the result
The preservation ZIP contains original source bytes, canonical review JSON, the selected export and extracted embedded attachments. This gives you a way to inspect unmapped fields and alternative values after a merge. Remote image URLs are retained as text, and the page never fetches them.
The page does not save contacts to browser storage. Reloading or resetting clears the working session, so download the archive before leaving. It contains personal information and potentially several original copies of contact records. Store it where you would keep an address-book backup, and remove temporary exports when you no longer need them.