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CSV Import Mapper & Converter

Convert your CSV to the format your app needs

Match your columns to Shopify, HubSpot, Mailchimp or your own template, convert values safely, and download a ready-to-import CSV — all in your browser.

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About this tool

Every app wants its import file a little differently: Shopify needs an “Email” column and yes/no values, HubSpot wants phone numbers with a country code, Mailchimp wants birthdays as MM/DD. Your export from another system almost never matches.

CSV Import Mapper & Converter matches your columns to the destination’s format and tells you why it suggested each match. Anything uncertain waits for you to confirm. It converts values only where the rule is clear — dates in a known order, yes/no answers, country names to codes — and keeps everything else exactly as it is. Every row of your file stays in the converted file, and you get a report of where every column came from.

Useful for

  • Store owners moving customers into Shopify
  • Marketers moving contact lists between Mailchimp, HubSpot and other tools
  • Anyone given a template CSV by a new app or supplier

How it works

  1. Upload your CSV

    Add the file you exported, or try the sample. It is processed in your browser and never uploaded.

  2. Choose where it should go

    Pick Shopify customers, HubSpot contacts or companies, Mailchimp contacts — or upload your app’s template CSV.

  3. Match your columns

    See which of your columns goes where, with example values and the reason for each suggestion. Confirm anything uncertain.

  4. Check and download

    Preview the converted file, review anything flagged against the destination’s rules, and download it with a mapping report.

Why use it

  • Suggestions you can trust

    Every match says why it was made — “same name, different capitals”, “an older Shopify column name”. Guesses always wait for your confirmation.

  • Your data stays intact

    One row in, one row out. Leading zeros, long IDs, accents and dates are kept exactly as they are unless you choose a conversion.

  • Checked against official rules

    Each destination is built from the platform’s own import documentation and sample files, with the source of every rule shown.

  • Private by design

    The file never leaves your device. No account, no upload, no tracking of what’s in your data.

Your files and privacy

Your file is read and converted entirely in your browser, on this device. It is never uploaded to PuffinKit or anyone else, and the page is blocked from sending anything over the network while you work (we check this with automated tests). Nothing is kept after you close the page — only a mapping you choose to save stays in this browser, and it never contains your rows or values.

PuffinKit never changes your original files. See our privacy policy.

Frequently asked questions

Which apps can it convert to?

Shopify customers, HubSpot contacts, HubSpot companies and Mailchimp contacts — each checked against the platform’s official import documentation. For any other app, upload its template CSV or list the columns it needs, and the tool matches your file to that.

Will my file definitely import?

We can’t promise that — only the import itself can. The tool checks everything the platform documents for its import files, but your own account can add rules we can’t see (custom fields, dropdown options). Import a few rows first to test.

Does it ever change or drop my data?

Every row of your file is in the converted file, in the same order. Values are copied exactly unless you choose a conversion, and conversions never guess: a date like 03/04/2026 is converted only after you say whether it’s day or month first, and names are split only when they’re clearly two words. Anything that can’t be converted is kept as it is and flagged.

Is my file uploaded?

No. The file is read and converted in your browser, on your device. The page is blocked from sending anything over the network while you work, and our automated tests check this on every release.

What does a saved mapping keep?

Only which of your columns go where and how values are converted — column names and settings, never your rows or values. It’s stored in this browser when you press Save (or downloaded as a file), and you can delete it at any time.

Can it read Excel files?

Not directly. In Excel, choose File → Save As → “CSV UTF-8 (Comma delimited)”, then add that file. Before you do, check that long numbers and codes with leading zeros look right — Excel can change them before they’re ever saved.

My file has errors (broken quotes, misaligned rows). Can it convert it?

If part of the file can’t be read reliably, the converter stops rather than guess where values belong. Repair the file first with CSV Import Error Repair, then convert the repaired file.

How large can the file be?

Up to 50 MB on a computer and 15 MB on a phone or small tablet. Some destinations have their own limits — Shopify accepts customer files up to 15 MB — and the tool tells you if the converted file is larger.

Do I need an account?

No. You can use this tool without signing up.