Last updated May 2026
Vellum does not collect, store, transmit, or sell any personal data.
Vellum injects CSS and a canvas animation into claude.ai and chatgpt.com to apply your chosen theme. It does not read, modify, or transmit any conversation content, personal information, or browsing activity.
Your selected theme, Pro status, and license key (if applicable) are saved using Chrome's built-in sync storage. This data stays within your browser and syncs across your devices through your Google account. Vellum has no server and cannot access this data.
When you activate a Pro license key, Vellum sends the key to Lemon Squeezy's API (api.lemonsqueezy.com) to verify it is valid. This is the only external network request the extension makes. No personal data is included in this request.
None. No analytics, no telemetry, no cookies, no fingerprinting, no tracking scripts of any kind.
The only external service involved is Lemon Squeezy for payment processing and license validation, governed by their own privacy policy. Vellum does not share data with any other third party.
If this policy changes, the updated version will be published at this URL. Vellum will never introduce data collection without clear notice to users.
Questions can be sent to hello@vellum.app.