Upcoming Windows toolchain update to VS 2026 and SDK 26100.7705

[Devon Loehr]

We are about to land a CL that will update Chromium to build using the most recent windows tools, most notably Visual Studio 2026. For googlers building on corp devices, no action is needed -- the new tools will be picked up automatically by `gclient sync`.

For everyone else, please make sure your computer has the latest version of both Visual Studio and the windows SDK (10.0.26100.7705), which can be installed as a component of Visual Studio or from Microsoft's website.

As with previous toolchain updates, please wait 2 weeks after the CL lands before you begin relying on any new features -- this gives us time to detect any hidden issue and revert the update if necessary. During that time, we will continue to support VS 2022 and the old SDK version on a best-effort basis, but that support will end afterwards.

--Devon Loehr

[cyberrufus]

Updated build instructions for Windows suggest that an EV for the installation location may be required (vs2026_install). Appears this issue has also been addressed. Is this correct?

[Pratyush Mohanty]

Dear Devon,

Yes—this is correct. For standard (default) Visual Studio 2026 installations, Chromium’s Windows toolchain detection will pick up VS 2026 automatically (via normal VS discovery), and setting an environment variable such as vs2026_install should not be required.

The vs2026_install variable is only relevant as a fallback for non-standard setups (for example, a custom install location or if automatic discovery fails). If detection works, it should be left unset.

After the CL lands, ensuring VS 2026 and Windows SDK 10.0.26100.7705 are installed and then re-syncing/re-generating (e.g., gclient sync, then re-running gn gen) should be sufficient.

Sincerely,
Pratyush Mohanty

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