I built a preflight checker for Shopify CSV imports — free in-browser check, $19 one-shot fix

Shopify's product CSV import fails in ways that are hard to debug: two-stage validation, silent partial failures, and duplicate handles that overwrite existing products. Migration apps (Matrixify, Ablestar) solve this as a monthly subscription, which is overkill if you import twice a year.

So I built the boring middle option: Preflight Kit, a browser-side validator. Drop the CSV, get row-level findings in seconds, nothing uploaded anywhere. Monetization is a $19 one-shot (fixed CSV + error list + human report) instead of a subscription.

Current stage: tool is live and free, first paid conversions are the open question. Happy to share what I learn about validating demand for "insurance-type" dev tools.

Try it here: https://preflight-kit.pages.dev/