Will this file import into Mailchimp?
Find out before you upload. This checks your spreadsheet against Mailchimp's real audience contacts rules, maps your columns to its field names, and shows you exactly which rows would be rejected — with row numbers.
Runs in your browser. Nothing is uploaded.
Drop a CSV or Excel file here
Or choose a file — nothing leaves your browser.
Mailchimp only truly requires an email address, but its Birthday field takes month and day only — a full date is the classic silent failure here.
- Email Address — used to deduplicate
- Email Address is the only required column for email contacts.
- Birthday must be month-day (MM/DD), not a full date — the year is not accepted.
- Tags go in a single column named Tags.
Common questions
Which columns does Mailchimp require for audience contacts?
Email Address. Rows missing it are rejected. This page checks every row for you and lists the ones that would fail.
Why did my Mailchimp import fail?
Mailchimp only truly requires an email address, but its Birthday field takes month and day only — a full date is the classic silent failure here. Drop your file above and you'll get a row-by-row list of what Mailchimp would reject, with the row numbers.
Is my file uploaded anywhere?
No. The mapping and validation run entirely in your browser using JavaScript. Your spreadsheet never reaches our servers, which matters when the file is a customer list.
Does it change my data?
It renames your column headers to Mailchimp's exact field names and reformats values that Mailchimp would otherwise reject — phone numbers, yes/no fields and picklist casing. Every change is listed before you export, and nothing that can't be safely converted is touched.
Field rules sourced from Mailchimp's own documentation.