Sync Theme

Switches Gmail, Grafana, and Slack between light and dark to match your system theme. Works only on those sites.

Sync Theme keeps Gmail, Grafana, and Slack in step with your operating system's light/dark setting. Flip your OS to dark mode and your open Gmail, Grafana, and Slack tabs follow automatically — and back to light when you switch back. Features • Works on Gmail, Grafana (Grafana Cloud and self-hosted), and Slack web. • A master on/off switch plus a per-site toggle, so you can run just the sites you want. • Add self-hosted Grafana instances on your own domains — you approve each one through Chrome's permission prompt. • No accounts, no tracking, no data collection, no remote servers. How it works When your OS theme changes, Sync Theme switches each site using that site's own built-in light/dark control, so it looks exactly as the site intends — including custom Slack workspace themes. It runs only on Gmail, Grafana, and Slack, never on other sites, unless you explicitly add a self-hosted Grafana domain on the options page. Privacy Sync Theme does not collect, transmit, or sell any data. Your on/off preferences sync through your own Chrome account; any self-hosted domains you add stay on your device.