I came across this website last week when Europe was a no-fly zone. Yesterday I was able to track my wife's flight from Dublin to London Gatwick, which www.flightstats.com said it couldn't track. No registration or fees involved. But I wonder how accurate it is, & how comprehensive, e.g. it currently shows lots of flights in Europe, Brazil, California, but only one or two other places, & only one flight in the whole of Australia. Has anyone else used this or other sites?

http://www.flightradar24.com

I use flightaware.com. I find it very accurate for US flights, and so-so at best for US-international flights. I haven't tried to use it for intra-Europe or Australia.

Given that there are many separate flight control agencies in Europe, not one centralized flight control operations, I doubt there is a good database for Europe flights available to these tracking websites.

Also, in the US the FAA doesn't report all flights - private flights can request to be kept private and not be reported.

flightradar24 is a Euro-centric site, just like flightaware is US-centric.

FlightAware works for the U.S., but not other countries. They show just about all civilian flights that have filed IFR and haven't specifically requested to be excluded. This notably includes all commercial airline flights.

There are other sites, such as flightradar24, that show flights on a real-time basis, but most of them depend on networks of private ADS-B receivers ... which means that they only show airplanes with ADS-B equipment (most commercial airliners, but not many other types of planes), and they only show traffic in areas covered by their network of receivers, so some areas may look busy and others may look blank. For example, this particular site shows tons of flights over Germany and the UK, where it has lots of volunteers with receivers, but practically none over France or Spain, because it has almost no volunteers in those areas.

Hmmm, I just tried to use flightaware.com to track TS 811, Air Transat from Glasgow to Toronto which departed Glasgow at 1430 today (UK time) & is due to arrive Toronto 7 hours later. But FlightAware gives me Air Transat #811 which it insists is TSC 811, (not TS 811) flying from Juan Gualberto Gomez Int'l (MUVR / VRA) (Cuba) to Halifax Int'l (CYHZ) Nova Scotia. It tells me the date was Tuesday, 01 May 2007 & it landed 3 years ago! I tried a few times, same every time. Flightstats gives the correct flight but says it can't track it, probably as it's over a large body of water (which makes sense). I'm giving up.

FlightAware is not reliable for flights outside the United States.