Klaviyo profile import file formatter: a CSV a list import accepts
In short: Upload any export (.xlsx or CSV) or paste cells. The tool writes Email, Phone Number, First Name and Last Name with lower-case emails and +country-code phones, merges repeats and warns above 50 MB. It writes no consent columns. Limit: Only Email, Phone Number, First Name and Last Name are written; map other properties in Klaviyo.
Klaviyo's list import takes a CSV of 50 MB or less whose first column is labeled Email or Email Address, or Phone Number. Upload your export here and it writes Email, Phone Number, First Name and Last Name, with lower-case emails, phones in +country-code form and repeats merged. No consent columns are created.
Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. Check your list free nowSee pricing
Used only to complete phone numbers.
Sample result
Jane, Leo and a phone-only contact become three profiles under Email, Phone Number, First Name and Last Name.
- Profiles
- 3 profiles
- File limit
- 50 MB
- Repeats merged
- 1
What this means for you
A profile needs an email or a phone number; no consent columns are written, so you add those yourself.
- Email or phone is enough
- +country-code phones
- Repeats merged
- 50 MB warning
- Klaviyo
- Profiles
- CSV
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
Check the addresses before they go into Klaviyo.
- Export the email column from the file you just made, or use the check button under the result.
- Upload or paste it at /verify. Every address gets a live mailbox check, and the first 100 email checks are free with a Google sign-in, no card.
How do I prepare a CSV for a Klaviyo list import?
- Upload the export (.xlsx or CSV), or paste the cells with the header row first.
- Choose the country used for phone numbers written without a + country code.
- Check the columns found, then download the CSV.
- In Klaviyo, open the list, choose to add contacts by uploading a CSV, and confirm the column mapping.
Example
- You enter
- A sheet with Full Name, Work Email, Mobile, Country and Company:
Jane Doe,[email protected],(415) 555-0132,United States,Northwind;Leo Martinwith[email protected]; [email protected]; a repeat row for[email protected]; and a row with only a phone,(212) 555-0100. - You get
- Three profiles under Email, Phone Number, First Name and Last Name: Jane with
+14155550132, Leo with[email protected], and the phone-only row as+12125550100. The repeat is merged, and a note says no consent columns are written. - Limits
- Runs in your browser; nothing is uploaded. Files up to 25 MB.
What does Klaviyo's list import require?
Klaviyo's list import article says the CSV must be 50 MB or less, and that the first column should hold email addresses labeled Email or Email Address, or phone numbers labeled Phone Number. See Klaviyo's import guide. This tool puts Email first and writes Phone Number, First Name and Last Name after it.
What about consent?
Klaviyo's article describes consent columns with values such as Subscribed, Unsubscribed and Never subscribed. This tool does not write them: whether a person agreed to hear from you is a fact only you can state, so add those columns yourself, and only for people who did.
How are rows cleaned?
Emails are trimmed, lower-cased and checked for a valid shape; a cell with several addresses keeps the first. Phones become +country code and number using the country you choose. A row is kept when it has an email or a phone, and repeats of one address are merged.
Who uses this tool, and for what?
- Ecommerce marketers
- Prepare a customer export for a Klaviyo list with clean emails and phones.
- Agencies
- Move a client's contacts from another email platform with one consistent file.
- Store owners
- Fix messy spreadsheet columns before importing subscribers.
What can’t this tool tell you?
- Only Email, Phone Number, First Name and Last Name are written; map other properties in Klaviyo.
- No consent or timestamp columns are created.
- Klaviyo's article doesn't state a phone format, so numbers use +country code and number; confirm on the mapping screen.
- Phone numbers that can't be read are left blank and counted.
Common questions
- What size can a Klaviyo CSV import be?
- 50 MB or less. Larger files must be split into several CSVs.
- What should the email column be called?
- Klaviyo's article says Email or Email Address, with phone numbers labeled Phone Number.
- Does this tool add subscription consent?
- No. It writes no consent columns; add them yourself for people who agreed.
- Can I import profiles with only a phone number?
- Yes. A row with a valid phone and no email is kept, and the phone is written in +country-code form.
- Is my list uploaded to SimpleVerifier?
- No. The file is read and rewritten in your browser.
Sources
A tidy list can still be full of dead addresses.
Extracting, deduplicating and syntax checks all work on the text of an address. None of them can tell whether the mailbox exists. Only the server that hosts it can answer that, through an SMTP check, and that is what the paid product does.
- Upload the cleaned file as it is: CSVs up to 100,000 rows
- A real SMTP mailbox check on every row, with catch-all detection
- Small list? Starter at $9/mo covers 2,500 emails a month, cancel anytime
Plans from $9 a month, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.