Last updated · 19 June 2026
The short version: Kiln is local-first. Your prompts, API keys and generated images stay on your Mac. Kiln has no account system, runs no analytics or telemetry, and we operate no server that sees your data. This policy explains the little data that is involved and who handles it. It applies to the Kiln app and the website at runkiln.app, and the data controller is Erwan Rombo, based in Barcelona, Spain.
Everything you do in the App is stored locally on your own device: your prompts, your run history, the images you generate, and your settings. Your provider API keys are stored in the macOS Keychain. None of this is sent to us — we have no server that receives it and no way to read it.
When you run a comparison, Kiln calls the AI providers you have configured (such as OpenAI, Google and Fal) directly from your Mac, using your own API keys. The prompts and any reference images you include are sent to those providers so they can generate results, and they handle that data under their own privacy policies. Kiln does not proxy, copy or store these requests.
When you buy Kiln, the transaction is handled by Lemon Squeezy, our Merchant of Record. Lemon Squeezy collects the information needed to process the payment — such as your name, email address, billing country and payment details — under its own privacy policy. We receive a limited record of the order (including your email address and what you bought) so that we can deliver your licence and provide support. We do not receive or store your full payment-card number.
We use the email address from your purchase only to deliver your licence and download, to notify you when the App launches, and to respond to support or refund requests. We do not sell your data or share it for advertising. You can ask us to remove your email from our records at any time.
The Kiln website is a static site hosted on Cloudflare Pages. It does not set advertising or tracking cookies. The hosting provider may process standard, aggregated request logs (such as IP address and browser type) for security and reliability, as is normal for any website.
Because we are based in the EU, you have rights under the GDPR — including the right to access, correct or delete the limited personal data we hold (essentially your order email address), and to object to its processing. For data held by Lemon Squeezy as Merchant of Record, you can also exercise these rights through them. To make a request, email [email protected].
We keep order records only as long as needed to provide the product, support and to meet legal or accounting obligations. Data stored locally in the App stays on your Mac until you delete it.
Kiln is not directed at children and is not intended for use by anyone under the age of 16.
We may update this policy from time to time. The current version is always the one published on this page, with the “last updated” date above.
Questions about your privacy or your data? Email [email protected].