Responsive Tester Privacy Policy
Last Updated: July 10, 2026
Responsive Tester is built to keep your data on your device. To do its job it works with the content of the page you are previewing and with your interactions, but this happens locally in your browser, in real time. Nothing is recorded, and the only thing that ever leaves your device is a license key sent to verify a purchase. This page describes exactly what the extension handles and how.
1. What the Extension Handles
To function, Responsive Tester works with the following. It does not record, log, or transmit any of it, except the license key as noted.
- Website content: To preview a page across viewports, the extension reads the current page's structure, styles, and stylesheets in order to render it in each frame, build the live CSS editor, and capture screenshots you request. This is processed locally in your browser and is never stored or transmitted.
- Your interactions (user activity): When interaction sync is on, your clicks, scrolling, and typing are mirrored across the open viewports in real time so every screen stays in sync. These interactions are handled locally and momentarily to drive the mirroring. They are not recorded, stored, logged, or transmitted.
- License key (authentication): If you purchase a license, your key (issued by Gumroad) is stored locally on your device and sent to Gumroad to verify the purchase. It is the only piece of data the extension transmits off your device. See Data Sharing below.
- Settings: Your viewport list, zoom level, theme, and toggle preferences are stored locally.
- Analytics: There are none. No trackers, no telemetry, no usage statistics.
- Payment information: Never seen or stored. All payments are processed by Gumroad.
2. How Data Is Used
Each item above is used only for the feature it supports, and for nothing else:
- Rendering and editing: Page content is used only to display the page in the viewports, power the live CSS editor, and produce screenshots you ask for. It stays in your browser.
- Keeping viewports in sync: Your interactions are used only to mirror the same action across the open viewports as it happens.
- License validation: Your license key is verified against Gumroad's license API to confirm the purchase and enforce activation limits.
- Feature access: Your license or trial status determines whether Pro features (interaction sync and live CSS editing) are unlocked.
- Preferences: Your stored settings restore your viewports, zoom, theme, and toggles between sessions.
None of this data is sold, and none of it is used for any purpose beyond the features described here.
3. Data Sharing
The only third party that ever receives anything is Gumroad: license validation requests contain the license key and the product id, nothing else. You can review Gumroad's practices at gumroad.com/privacy. No data is shared, sold, or transferred to anyone else, ever.
4. Data Storage
Everything the extension stores lives on your device, in your browser's local extension storage. Nothing is written to any server. Removing the extension removes its stored data.
5. Free Trial
The free trial is tracked with a start timestamp stored locally on your device. It never leaves your machine and is not linked to any account or identifier.
6. Third-Party Services
- Gumroad: Payment processing and license verification. Sees your payment details at checkout and license keys during validation.
- responsive-tester.app: This website hosts the welcome page and the license validator. It runs no analytics and sets no tracking cookies.
- Google Fonts: This website (not the extension) loads fonts from Google Fonts, which involves a standard font request to Google's servers.
7. User Rights
All stored data lives on your device, under your control. Removing the extension removes it. For any questions or requests, contact violetsmyster@gmail.com.
8. Changes to This Policy
Updates to this policy will be posted on this page with a new "Last Updated" date.
9. Contact
Questions about this policy: violetsmyster@gmail.com.