There are two main issues that can cause your video to stutter or freeze: computer performance and network performance.
Computer performance
- Power saving features may cause your computer to run at less than maximum performance, especially when not plugged in. Plug in your computer or adjust your computer settings for power management to run at maximum performance.
- Exit other applications (or close other tabs) that may be running in the background.
- Review the minimum system requirements to ensure that your hardware is capable of casting a tab.
Network performance
- Casting a tab requires a good Wi-Fi connection. To get a better connection, move your router closer to your TV or adjust the position of your Chromecast device.
- If your computer has the option of using a wired connection, or if it can connect to your network using 5 GHz, this may yield better performance (so your computer and Chromecast aren't sharing available 2.4 GHz bandwidth, note that your Chromecast must be set up first). For this to work, Access Point (AP) Isolation or Client Isolation mode must be turned off on your router. Learn more about AP Isolation or Client Isolation.
- Other apps such as streaming and media apps, and devices on your network may be reducing available bandwidth. Minimizing these may help.