Extension Privacy Policy

Last updated: April 2026
Overview

Base16 Everything is a browser extension that remaps website colors to match your chosen color scheme. This policy describes precisely what data the extension collects, why, and how it is handled. All color processing is performed locally on your device — the extension never reads or transmits page content.
Data Collected by the Extension
1. Device key pair (stored locally)

On first activation, the extension generates a random ECDSA P-256 cryptographic key pair using the browser’s built-in WebCrypto API. The private key never leaves your device and is stored only in the extension’s local storage. The public key is used to identify your device installation for license enforcement.

This key is entirely random and contains no information about your hardware, browser version, installed fonts, screen resolution, or any other personal or device characteristic.
2. License key (stored locally)

If you activate a premium license, your license key is stored in the extension’s local storage. It is sent to our server only during license verification.
3. Theme preferences (stored locally)

Your chosen color schemes (light and dark), per-site toggle states, and other settings are stored locally in the extension’s storage. They are never transmitted to any server.
4. Color mapping cache (stored locally)

Computed color remappings are cached in the extension’s IndexedDB to avoid recomputing them on every page load. This cache contains only CSS color values, never page content, URLs, or personally identifiable information.
Data Sent to Our Server

The extension contacts base16everything.com only for license verification. No data is sent for free-tier users who have not entered a license key.

For premium users, the following is sent during license verification:

Your license key
The public half of your device key pair (a random value — no hardware data)
A cryptographic signature proving ownership of the corresponding private key
Browser family (e.g. “Chrome”) and OS family (e.g. “Linux”) — coarse labels derived from the user-agent string, used only as display names in your device list


The server stores the SHA-256 hash of your public key as a device identifier, along with the browser and OS labels. No IP addresses are stored beyond standard server access logs (retained per hosting provider policy). No browsing history, visited URLs, or page content is ever transmitted.
Permissions Used

storage — to persist your settings, license key, device key pair, and color cache locally.
activeTab / tabs — to apply color remapping to the current tab and read the active domain for per-site settings.
scripting — to inject the color-remapping CSS into web pages.
nativeMessaging (optional, premium) — to read your local Base16 theme configuration from ~/.config/base16_everything/config.yaml. Used only if you explicitly enable system theme sync. No data from this file is sent to any server.
<all_urls> — required to inject CSS into any website you visit. The extension only reads CSS color values from the page; it does not read text, form data, or any other content.


Data Sharing

No data collected by the extension is sold, rented, or shared with third parties for advertising or tracking purposes. License verification data is processed by Supabase (database infrastructure) and Vercel (hosting), both of which act as data processors under our control.
Data Retention and Deletion

All locally stored data (settings, license key, device key pair, color cache) can be cleared at any time by removing the extension.

Server-side device records can be deleted from your account at base16everything.com/devices. License records are retained as long as your account is active and deleted upon request.
Children’s Privacy

The extension is not directed at children under 13 and does not knowingly collect any data from them.
Changes to This Policy

If this policy is updated in a material way, the “Last updated” date at the top of this page will be changed. Continued use of the extension after such changes constitutes acceptance of the updated policy.
Contact

Questions or requests regarding your data can be directed via support@base16everything.com