Check your supplier file
before it breaks your store.

About to bulk-import a supplier spreadsheet into Shopify? Preflights checks it first and shows you what would delete existing variants or import the wrong prices — the mistakes you can't undo once they're live. Add your Shopify export to also catch price and stock conflicts. Upload your file and get a plain report in seconds. We only read your files; we never connect to your store.

Read-only·no store connection·your raw file is never stored·EU-hosted

Why it's different

Free checkers read your file. We read it like Shopify will.

A free CSV validator can tell you a file is tidy. It can't tell you that this file will wipe out variants you already sell when it's imported — because it only checks formatting, not the structural pattern that causes Shopify to delete variants. Preflights catches that straight from your supplier file — no store connection needed. Add your Shopify export too, and we'll also flag price and stock conflicts against what's live in your store right now.

Two mistakes you can't take back once they're live.

Most import problems are annoying. These two are the ones that lose products or lose money — and they're the reason a pre-import check is worth paying for.

Can't be undone

An import that deletes your live variants

When a supplier file's option columns don't line up with how your products are already built, a Shopify import can remove the existing size and color variants on those products. Shopify imports can't be undone — there's no rollback. We check your file's own option structure for that pattern and flag every product at risk, straight from the supplier file — no store export needed.

We show you exactly which products are at risk.

Silently overwrites products

Two products sharing one handle overwrite each other

A product's handle is its unique address in Shopify. When two rows in your file carry the same handle, the import doesn't make two products — it merges them into one, quietly overwriting the first with the second. We flag every handle that appears more than once, so you catch the collision before it silently rewrites a live product.

A flag to confirm, not a guess we hide.

Everything else

…and 7 more checks, in the same pass.

The inspection also flags the issues that get products rejected by Google Merchant Center or quietly break your listings — each with the reason it matters and the fix.

Built for people who import other people’s spreadsheets.

Preflights is sharpest for agencies and supplier-fed merchants — the people who repeatedly handle catalog files they didn’t create. If your products come from a distributor sheet, not an auto-sync app, every bulk import is a risk.

Shopify agencies & freelancers

You migrate stores and onboard suppliers for clients whose data you don't control. One bad import becomes your emergency and your reputation. Inspect every client file before it touches their live store — and hand the report to the client as proof you checked.

Wholesale & branded merchants

You source from real distributors and update catalogs from supplier sheets in formats you didn't choose. Every refresh is a chance to delete variants or overwrite a live product by handle. Check the sheet before the import.

Probably not for you if…

  • your catalog is first-party and clean — you author every product yourself
  • you run clean API-based sync and never touch CSVs
  • you import a handful of SKUs and can eyeball them by hand
  • you already trust your import tool’s preview, backups and undo
Where it fits

Not another import tool. The safety check before the import tool.

Preflights is read-only and never connects to your store. Use your import tool to execute changes — use Preflights first to know whether those changes are safe.

Why not just use Matrixify?

Matrixify is the best tool to execute a bulk import — but its checking runs inside the app, after you’ve installed it and committed to importing, and even its own Dry Run admits it can’t catch everything Shopify rejects. Neither warns you about the silent data-loss: the 100+-variant rows Shopify drops without a word, or two products sharing a handle that quietly overwrite each other. Preflights catches those before you import — free, no install, no spreadsheet skills. Check here first, then import with Matrixify with confidence.

Why not just ask AI?

General AI can explain a spreadsheet, but Shopify import safety needs repeatable checks, row-level evidence, and deterministic validation. Preflights applies Shopify-specific rules and uses AI only to explain findings and suggest fixes — never to decide whether your import is safe.

The deliverable

You get a plain report: safe, review, do-not-import.

This example is generated from the bundled supplier CSV + Shopify export sample, so the counts below come from the same deterministic engine your upload uses.

Real pain

What merchants say about bad imports

"tons of wrong configured products … absolutely no control."

Shopify merchant

"mismatch price … wrong variant photos … titles reused across variants."

E-commerce agency

"every import leaves me riddled with anxiety — 5-minute job, or 3-day job."

Shopify merchant

Check the file before you import it.

Upload your supplier file and Shopify export. Your risk summary is free and instant — read-only, no store access.

Run a free inspection