Legal

Terms of service

Last updated 9 September 2026

These terms govern your use of websites and applications operated by Hill Labs LLC (“Hill Labs”), including Zipf at zipf.app. By creating an account or subscribing, you agree to them.

Your account

You are responsible for activity under your account and for keeping your login credentials secure. You must be old enough to form a binding contract where you live. Our services are not directed at children under 13, and in the European Economic Area and the United Kingdom you must be at least 16 to create an account without a parent’s consent.

Subscriptions and billing

• Paid plans are billed in advance through our payment processor on a recurring basis until cancelled.
• Where a free trial is offered, it converts to a paid subscription only if you choose to subscribe.
• You can cancel at any time from your account. Access continues to the end of the period already paid for.
• Prices may change. We will give notice before a change affects a renewal.
• Digital service, immediate access. When you subscribe, you ask us to begin providing the service straight away. Where you have a statutory right to withdraw from a distance contract within 14 days, you acknowledge that we begin performance at once with your express consent. In practice this costs you nothing: under our refund policy any charge can be refunded in full within 14 days, no explanation required.

Acceptable use

Do not use our applications to break the law, infringe someone else's rights, attempt to gain unauthorised access, or place an unreasonable load on the service. We may suspend accounts that do.

AI-generated output

Some features produce output using AI models. Output may be inaccurate. Review it before relying on it, particularly for anything consequential.

Availability and warranties

We work to keep the service available but do not guarantee uninterrupted operation. The service is provided "as is" without warranties, to the extent permitted by law.

Limitation of liability

To the extent permitted by law, our total liability arising from your use of the service is limited to the amount you paid us in the twelve months before the claim.

Changes and termination

We may update these terms; material changes will be posted here with a new date. Either of us may terminate the agreement, and you may stop using the service at any time.

Governing law and contact

These terms are governed by the laws of the State of Oregon, United States. Questions: [email protected]