Privacy Policy

Last updated: August 16, 2026

TenMil.ai is local-first. Your spreadsheets are parsed and merged inside your browser, not on our servers. This policy explains that architecture precisely, including the one place where a small sample of your data does leave your machine.

Local-first processing

File parsing, joins, filters, dedupe, and export all run in your browser's memory using a local SQL engine (DuckDB compiled to WebAssembly). Your files are never uploaded to us, never written to our storage, and are discarded from memory when you close or reload the tab.

What we send to plan a merge

To turn your plain-English request into a merge plan, we send a small sample of your files to our AI service over an encrypted connection. That sample covers your column names, the shape of each file, a limited number of example values from the columns being matched, and aggregate statistics about those columns.

If the columns being matched contain personal information — names, email addresses, customer IDs — then a limited number of those real values are included in the sample. Your full dataset is not.

Account and email data

If you create an account, we store your email address and authentication records through our hosted backend so you can sign back in. If you download a result without an account, we may ask for an email address; we store it to send you the file and to contact you about the product. You can ask us to delete it at any time.

Payments

Paid plans are processed by Stripe. Card details are entered on Stripe's systems and are never seen or stored by us. We retain only the subscription status and identifiers Stripe returns so we know which plan your account is on.

Analytics

We use PostHog for product analytics. Events carry counts, sizes, durations, and enum-like metadata only — for example the number of rows merged, the join type used, or a coarse error code. We do not send row data, column names, file names, or your prompts. Error messages are scrubbed of identifiers and literal values before they are recorded.

Cookies and local storage

We use browser storage to keep your session signed in, remember interface preferences, and record whether you have already seen certain prompts. We do not use advertising cookies or sell data to advertisers.

Data retention

Spreadsheet contents are never persisted on our servers, so there is nothing for us to retain or delete on that side. Account data is retained while your account is active. Analytics events are retained in aggregate.

Your rights

You can request access to, correction of, or deletion of the personal data we hold about you — which in practice means your account email, any email you gave us for a download, and your billing record. We will action verified requests within 30 days.

Changes to this policy

If we change what leaves your machine, we will update this page and the date above before the change ships.

Contact

Questions about this policy or a data request: reach us through the contact form on the TenMil.ai homepage.