Cross-domain tracking with the Treasure Data JavaScript SDK's td_global_id requires a browser that allows a third-party cookie to be read back on a different domain than the one that set it. Whether that works depends entirely on the browser, not on a version-by-version compatibility list — modern browsers apply a single default policy across all their supported versions. Use this page to confirm whether a visitor's browser can carry td_global_id across your domains before you rely on it.
| Browser | Supports 3rd-Party Cookies for Cross-Domain Tracking |
|---|---|
| Chrome, Edge | Yes. Both still allow third-party cookies by default as of 2026 — Google retired Privacy Sandbox and confirmed it will not deprecate third-party cookies in Chrome. |
| Firefox | No. Total Cookie Protection, the default in Standard mode, double-keys every third-party cookie to the top-level site, so td_global_id is set but never shared between your domains. |
| Safari (desktop and mobile) | No. Safari has blocked all third-party cookies by default since Safari 13.1 (March 2020), with no exception for td_global_id or any other cross-site cookie. |
For the full comparison of client-side, server-side, and storage restrictions behind these defaults, see About Treasure AI and Cookie Tracking. For the SDK configuration, see Enabling Cross-Domain Tracking With JavaScript SDK.