# Browsers That Support 3rd Party Cookies and TD JavaScript SDK

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](/products/customer-data-platform/integration-hub/streaming/td-javascript-sdk/about-treasure-data-and-cookie-tracking). For the SDK configuration, see [Enabling Cross-Domain Tracking With JavaScript SDK](/products/customer-data-platform/integration-hub/streaming/td-javascript-sdk/enabling-cross-domain-tracking-with-javascript-sdk).