Another website that I find very useful is the Ofcom Broadband availability checker.
https://checker.ofcom.org.uk/en-gb/broadband-coverage
This gives a more accurate result. The
https://bidb.uk/ website has recently from a few months failed to show Community Fibre being available for my postcode and a few nearby. It always fails to show Hyperoptic in any of the postcodes. I've only seen it display as "Hyperoptic is local" and also, Openreach FTTP fails to show as live in many of the postcodes.
Another thing I noticed is that BidB will show Virgin Media is live (2000 Mbps - XGS) for postcodes that would otherwise show as nexfibre under the Ofcom checker. This can be confusing for certain individuals who do not know if this is a native Mustang FTTP upgrade or a Nexfibre upgrade.
As always, I'd use the Better Internet Dashboard for viewing street works in the map but not rely on it as an availability checker.
The thinkbroadband labs site
https://labs.thinkbroadband.com/local/index.php also, fails to show nexfibre XGS-PON availability for certain postcodes like E3 4TD for the new Windermere development in Mile End, London. Not that I care, as I don't live there but just something I spotted as I was looking to compare different postcodes under my Housing Management.
You can also, view Uswitch and MoneySuperMarket as they fetch details about what's available when you select an address. But keep in mind that it can be inaccurate as both Uswitch and MoneySuperMarket are showing Virgin Media as available for my postcode (for years) when it has never been available. I have reported this to Uswitch and MoneySuperMarket a couple of years ago informing them that Virgin Media is not available for both postcodes of my building but they never bothered to correct the error.
Anyway, use the checkers as a rough reference guide and then compare it to the official website and see if what shows up is available. Sometimes a provider can be available but not show up in the checker and you may think it's not available and vice-versa.