Your statements are never stored.
Never sold.

Butter reads the visible text of checkout pages you visit — only to detect if you're on a checkout page and estimate the purchase amount. This analysis happens entirely in your browser. No page content is sent anywhere.

Your card wallet — a list of card product names you own — is stored in Chrome's encrypted sync storage. This is never card numbers, CVVs, or account details. Chrome encrypts this data and syncs it only between your own signed-in devices.

When you click Apply, we may receive a referral fee if you're approved, including through partner networks. This never influences our recommendations, which are based purely on your spending data and publicly available earn rates. Butter provides information and tools, not financial advice — always confirm card details with the issuer before applying.

The reward calculator on our homepage runs entirely in your browser. No data is sent to any server at any point.

When you upload a bank statement at /analyse, we never store the file or your statement data on our servers — processing is stateless and nothing is retained after your result is returned. Our fast local analysis runs entirely in your browser, and the file never leaves your device. If you choose AI-assisted analysis, the extracted statement text is sent to our processing endpoint and on to our AI provider (Google Gemini) solely to return your result. Before it leaves your device we strip card numbers, account numbers, postal codes, and phone numbers — but this stripping does not remove names or merchant details, so text sent to the AI provider may include your name as printed on the statement. For image-based or scanned PDFs that contain no readable text, we ask for your explicit permission before sending images of the statement pages to the AI provider for reading, since identifiers cannot be stripped from images beforehand. We use Google's paid Gemini API tier: under Google's API terms, your statement data is not used to train Google's models and is retained by Google only temporarily for abuse monitoring. Nothing is stored by us, and the original file is cleared from your browser's memory when you close the page.

We may use minimal, privacy-respecting analytics (no cookies, no personal identifiers) to understand site traffic. We do not use Google Analytics.