What file format does a Google Contacts import need?

A CSV (.csv) or a vCard (.vcf) file. An Excel workbook has to be saved as CSV first. If you are round-tripping data out of Google Contacts and back in, the Google CSV export option is the one that preserves every field, because its headings already match what the importer expects.

How many contacts can I import into Google Contacts at once?

Up to 3,000 per import, and Google's guidance for anything larger is to split the contacts into multiple CSVs before importing them. A Google account also holds a maximum of 25,000 contacts in total. Deduplicating first is worth doing before you start splitting — on a list assembled from several exports it often brings the file under the ceiling on its own.

Does Google Contacts remove duplicates from my import file?

Not during the import. Every row in your file becomes a contact. Afterwards, Merge & fix looks for duplicates and offers them as suggestions you accept individually or all at once — and it cannot merge contacts that are saved in different Google Accounts. So the duplicates get created first and cleaned up second, with the tool choosing the merge rather than you. Collapsing them in the CSV avoids that round trip.

Why did my columns land in the wrong fields after importing?

Because the header row is what tells Google Contacts where each column belongs, and yours did not match. Google's import template is explicit that the header row should not be deleted. It also uses paired columns — a label column that names the type of a detail, and a value column that holds the detail itself — so a file with a single unlabelled phone or email column can end up filed under the wrong type even when the data itself is correct.

How do I split a Full Name column for a Google Contacts import?

Split it into separate first and last name columns before you import, so each one maps to its own field in the template. The name splitter does this in the browser, handles rows written "Last, First", and can pull a middle name into its own column. Check the preview for the rows it could not split confidently — mononyms and two-word surnames are the usual suspects — then download the file.

Does Sigmera connect to my Google account?

No. There is no connector, no OAuth grant, and no API access to your contacts. The workflow is export, clean, import: you download the CSV from Google Contacts yourself, clean it in a browser tab, and import the result through Google's own Import button. Sigmera never sees your account and never asks for permission to.

Is cleaning a contact list in the browser safe under GDPR?

There is no transfer to account for. The CSV is read and rewritten by code running in your own browser tab, so the names, email addresses, and phone numbers in it are never sent to Sigmera or to any other server. No copy exists anywhere to be retained or deleted, and there is no processor to name for this step in your records of processing.

Clean CSVs for Google Contacts imports

A Google Contacts import is unforgiving in a quiet way: it does not reject your file, it just files the data wherever the header row points and leaves you to notice. Sigmera is not a Google connector and asks for no OAuth grant — you export the CSV, clean it in a browser tab, and import it through Google Contacts' own Import button. The file never leaves your device on the way through.

How it works

1
Export from Google Contacts, or start from the file you already have
In Google Contacts, choose Export, select which contacts to include, and pick Google CSV — that format round-trips back into Google Contacts with every field intact. If your list is coming from a phone backup, an old CRM, or a spreadsheet instead, any CSV works as a starting point.
2
Clean the file in your browser
Open the CSV in Sigmera and run the passes the list needs: remove duplicate rows, lowercase and validate the email column, rewrite phone numbers to E.164, split a full-name column into first and last. Each step previews before it commits, so you can check the rows a tool was unsure about.
3
Check the header row against Google's template
The headings are what map your data to the right fields, which is why Google's own guidance is not to delete the template's header row. Contact details come in pairs — a label column naming the type, such as Home or Work, and a value column holding the address or number itself — so a header that does not match leaves the data filed somewhere you did not intend.
4
Import the clean file
In Google Contacts, click Import, choose your CSV, and import. Sigmera has no connection to your Google account at any point: there is no OAuth grant, no API call, and no copy of the file on a server. The cleaning happened in the browser tab and the download went straight to your disk.

Common Google Contacts clean-ups

Deduplicate the export before it becomes 400 duplicate contacts

Contact lists accumulate: a phone backup, a Gmail auto-save, an old export, a spreadsheet a colleague sent. Merged into one CSV they contain the same people several times over. Google Contacts imports every row as written, then offers Merge & fix afterwards — a suggestion list you approve one at a time, and one that cannot touch contacts saved in a different Google Account. Collapsing the repeats in the file is the version where you decide which copy survives.

Open the export in the remove-duplicates tool
Match on the email column, ignoring case and surrounding spaces
Review the flagged rows and pick which copy to keep
Download the deduplicated CSV and import it

Rewrite the phone column to E.164 so numbers dial from anywhere

Google Contacts stores the phone number you give it. A column mixing (415) 555-0100, 415.555.0100, and 07700 900123 looks fine in the address book and fails the moment you dial one from another country, because a national-format number has no country code to fall back on. E.164 is the international standard form — a leading plus, then country code and number, no punctuation — which is what makes a stored number unambiguous wherever the handset happens to be.

Load the CSV and select the phone column
Set the default country for numbers written in national format
Rewrite the column to E.164 and check the rows that could not be parsed
Download and import

Split one Full Name column into the First and Last that Google expects

Google's import template gives names their own columns, so a CSV carrying a single Full Name field has nowhere correct to put it — every name lands in one box, and sorting, autocomplete, and mail merges all inherit the problem. Event platforms, web forms, and purchased lists almost always export the single-column shape.

Split the name column into first and last, with an optional middle name
Scan the compound surnames and the inverted "Last, First" rows
Map the resulting columns to the template's First Name and Last Name headings

Normalise the email column so the address book stays searchable

Addresses arrive with stray capitals, trailing spaces, and the occasional value that is not an email address at all. Google Contacts will store all of them. The cost shows up later: search misses the contact you typed in lowercase, and two spellings of the same address sit in the account as two people that Merge & fix may not connect.

Load the CSV and pick the email column
Lowercase and trim every address
Review the rows flagged as not valid addresses and decide whether to drop them
Download the cleaned file

Get a large export under the 3,000-contact import ceiling

Google Contacts imports up to 3,000 contacts at a time, and an account holds up to 25,000 in total. A 4,200-row export therefore fails as one file. Before you start cutting it into batches by hand, remove the duplicate rows and the rows with no usable email or phone — on a list assembled from several sources that routinely takes a few thousand rows off the count, and it is work you would have had to do after the import anyway.

Deduplicate on the email column and note the new row count
Clean the email column and drop the rows with no valid address
If the file is still over 3,000 rows, split it into batches in your spreadsheet
Import each batch through Google Contacts

Sources

Frequently asked questions

What file format does a Google Contacts import need?: A CSV (.csv) or a vCard (.vcf) file. An Excel workbook has to be saved as CSV first. If you are round-tripping data out of Google Contacts and back in, the Google CSV export option is the one that preserves every field, because its headings already match what the importer expects.
How many contacts can I import into Google Contacts at once?: Up to 3,000 per import, and Google's guidance for anything larger is to split the contacts into multiple CSVs before importing them. A Google account also holds a maximum of 25,000 contacts in total. Deduplicating first is worth doing before you start splitting — on a list assembled from several exports it often brings the file under the ceiling on its own.
Does Google Contacts remove duplicates from my import file?: Not during the import. Every row in your file becomes a contact. Afterwards, Merge & fix looks for duplicates and offers them as suggestions you accept individually or all at once — and it cannot merge contacts that are saved in different Google Accounts. So the duplicates get created first and cleaned up second, with the tool choosing the merge rather than you. Collapsing them in the CSV avoids that round trip.
Why did my columns land in the wrong fields after importing?: Because the header row is what tells Google Contacts where each column belongs, and yours did not match. Google's import template is explicit that the header row should not be deleted. It also uses paired columns — a label column that names the type of a detail, and a value column that holds the detail itself — so a file with a single unlabelled phone or email column can end up filed under the wrong type even when the data itself is correct.
How do I split a Full Name column for a Google Contacts import?: Split it into separate first and last name columns before you import, so each one maps to its own field in the template. The name splitter does this in the browser, handles rows written "Last, First", and can pull a middle name into its own column. Check the preview for the rows it could not split confidently — mononyms and two-word surnames are the usual suspects — then download the file.
Does Sigmera connect to my Google account?: No. There is no connector, no OAuth grant, and no API access to your contacts. The workflow is export, clean, import: you download the CSV from Google Contacts yourself, clean it in a browser tab, and import the result through Google's own Import button. Sigmera never sees your account and never asks for permission to.
Is cleaning a contact list in the browser safe under GDPR?: There is no transfer to account for. The CSV is read and rewritten by code running in your own browser tab, so the names, email addresses, and phone numbers in it are never sent to Sigmera or to any other server. No copy exists anywhere to be retained or deleted, and there is no processor to name for this step in your records of processing.

More import guides

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