https://wccftech.com/how-to/upgrade-windows-7-download-windows-10-free/

Yep, the free Windows 10 upgrade offer is still valid. After the launch of Windows 10 in 2015, Microsoft had offered users to download Windows 10 for free and upgrade Windows 7 to the newer operating system. The offer was “officially” valid for one year, ending on July 29, 2016.

However, as we continued to confirm months and years after that deadline, Microsoft kept allowing users to download the latest Windows version for free. End of service deadline for Windows 7 is in January, 2020 after which the operating system will stop getting updates from Microsoft. Since the deadline is just a few months away, multiple ads have started suggesting users to buy a copy of Windows 10. But, the official, free upgrade offer still remains valid.