MarginJar

Privacy

Last updated 21 July 2026

MarginJar is built so that the sensitive parts of your business never reach us in the first place. This page describes exactly what happens to your data, in plain language, and the architecture that backs it up.

Your CSV file is parsed in your browser and is never uploaded. When you import an Etsy export, the file is read locally by JavaScript running on your own device. Individual order rows — buyer names, addresses, order numbers, item-level transactions — are aggregated on your machine, and only the per-SKU totals leave it.

The free calculator

The fee and profit calculator on the home page and on every guide page performs its arithmetic synchronously in your browser. There is no request to any server while you type, no account, and no cookie. If you close the tab, the numbers are gone. You can verify this yourself: open your browser’s network panel, clear it, and change any input — nothing is sent.

What we store when you have an account

If you sign up, the following is stored in our database:

  • Your account identifier and email address, provided by our authentication provider (Clerk). We do not store or ever see your password.
  • Per-SKU aggregates from your imports — the SKU code, product title, number of units sold, total revenue, and total fees for that SKU over the imported period.
  • Cost baselines you enter — the material, shipping and labor cost you assign to each SKU.
  • Subscription state — whether you are on the free or paid plan, and the identifiers our payment provider (Stripe) needs to manage that.
  • An import log— the date and SKU count of each import, used to enforce the free tier’s one-import-per-month limit.

What we never receive

  • Raw CSV rows, in whole or in part.
  • Buyer names, shipping addresses, email addresses or order numbers.
  • Individual transactions — only totals grouped by SKU.
  • Your Etsy password or any Etsy API credential. MarginJar does not connect to Etsy.
  • Your card number. Payment details go directly to Stripe and never touch our servers.

Analytics

We measure page views and two product events — that a calculation happened, and that a result was copied — so we know which guides are useful. This is deliberately coarse:

  • No cookies are set for analytics, and no cross-site identifier is created.
  • We do not record the values you type into the calculator, ever.
  • Calculator events are counted in memory and sent once when you leave the page, so that using the calculator generates no network traffic at all.
  • We record a page path and a country code. We do not store IP addresses.

Third parties

MarginJar runs on Cloudflare Workers with a Cloudflare D1 database. Authentication is handled by Clerk and payments by Stripe. Each of those providers processes the minimum data needed for its function — Clerk sees your sign-in credentials, Stripe sees your payment details, and neither receives your product or margin data.

Your data, your call

You can delete your account at any time, which removes your SKU aggregates, cost baselines and import history from our database. Because we never held your raw CSV, there is nothing further to erase. To request deletion or a copy of your data, contact us from the email address on your account.

Changes

If this policy changes in a way that affects what we collect, the change will be reflected in the “last updated” date above and described here. The client-side-parsing guarantee is a design commitment, not a preference — it is not something we intend to walk back.