Google responds to global Chromecast outage with 'don't do this' warning

If you have tried to cast to your Chromecast and it's not working, it's not your fault, it's Google's as the company has recently acknowledge a widespread outage.

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Google Chromecast 2nd generation

The company has confirmed the widespread outage is a software-related issue and not an intentional phase-out of the devices. For those who aren't affected by the outage, reports indicate it's mostly affecting older Chromecast models, such as the 2nd-gen Chromecast released in 2015 and Chromecast Audio. Currently, Google hasn't revealed the cause of the outage but has warned users not to factory reset their devices as a means of troubleshooting, as it could permanently lock them out of the system.

Reports are now surfacing citing software engineers that have dug into the problem, with The Register speaking to Tom Hebb, a former Meta software engineer and Chromecast hacker, who published a detailed analysis about the outage. According to Hebb, the fix could take more than a month to be rolled out, and the problem stems directly from an expired device authentication certificate.

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"We're contacting you because of a disruption affecting Chromecast (2nd gen) and Chromecast Audio devices. We apologize for the issue and understand your frustration. We are working to roll out a fix as soon as possible and will share updates and guidance on the Nest Community page. We appreciate your patience as we resolve this issue," wrote Google

So, what does that mean? A Chromecast is essentially a media player that users can send requests to. These requests come from apps and arrive on the Chromecast in the form of a URL that the device then fetches from its respective service. For example, casting a Netflix movie to a Chromecast triggers the device to fetch the respective URL for the Netflix movie, then it displays it on the device.

For this process to be carried out, several layers of verification happen under the hood. Firstly, each Chromecast contains a cryptographic public-private key pair, which is installed at the factory and creates a device certificate. This certificate is then used as a digital signature that verifies the device is Google-made, which is then used by apps and services for casting purposes. Google-owned intermediate certificate authority verifies the signature of the device, proving it is Google-made, enabling applications and services to connect to it.

However, the validity of devices affected by the global outage expired on March 9, 2025, which means devices, services, and apps running on current validity processes are unable to verify the Chromecasts as the software checking for a valid signature cannot find one. Therefore, it's rejected and users are presented with the message their Chromecast device is "untrusted".

"Do not factory reset your device - we will keep you all updated when the fix rolls out. If you have already factory reset your device, we will provide instructions to set your device back up as soon as possible," wrote Google

Unfortunately, the fix isn't a simple update as some affected Chromecast devices have been factory reset, which means Google can't access them as the certificate bundled with the factory reset is now unauthorized. So, what can be done?

"Google will either need to put in over a month of effort to build and test a new Chromecast update to renew the expired certificates, or they will have to coordinate internally between what's left of the Chromecast team, the Android team, the Chrome team, the Google Home team, and iOS app developers to push out new releases, which almost always take several days to build and test," explained Hebb