Travel options from London to Edinburgh

Flying is the fastest option (1h10), but you'll have to take into account:

• traveling times to the airports: London City Airport is close to the city center (22 min to Bank Station), but Edinburgh Airport is not (35 min by the tram or 30 min by the slightly faster Airport 100 bus, or 25 min in light traffic if you're driving or taking a cab outside peak hours) – add also some waiting and walking time;
• time spent getting through security;
• time waiting in the boarding room or for check-in (15 to 30 min at least, depending on whether you have luggage or not).

So this will probably bring you closer to 3 hours total, city center to city center. Flying though London Heathrow will take even more time (to get there: 15 min train from Paddington station every 15 min, and because the minimum conformance times are higher). And even worse for Stansted: the Stansted Express, the fastest route available between Stansted Airport and Central London, takes 47 minutes from Liverpool Street.

London Gatwick and London Luton also offer a few flights to Edinburgh but have longer conformance times and are way further from the city (so there's no point flying from them if you're inside London, the train is faster). See here for the full list of airlines and destinations served from Edinburgh Airport.

By train, the fastest is with the East Coast Main Line: 4h20, running every hour from 7am to 7pm from King's Cross (some additional trains take ~5 hours). But there is also a sleeper service from London to Edinburgh (the Caledonian Sleeper Lowland Route), which can be interesting to gain time:

Travelling southbound, the Caledonian Sleeper departs from both Edinburgh Waverley and Glasgow Central at 23.40. On a Sunday the service leave a little earlier at 23.15. The Glasgow Central train stops at Motherwell with both trains then joining at Carstairs. The train crosses the border stopping at Carlisle and then at Watford Junction before arriving at London Euston by 07.10, plenty of time for breakfast before having a whole day in London. Travelling northbound the Caledonian Sleeper Lowland route sets off at 23.50 five nights a week and at 23.27 on Sundays. The train splits into two portions at Carstairs with arrivals to Glasgow Central at 07.20 and Edinburgh Waverley at 07.20.

On the East Coast Main Line, you can book up to 5 months in advance (excluding weekends and bank holidays, which can only be booked 3 months in advance).

Driving is not a fast option (over 7 hours), but an overnight bus can also be an efficient and cheap alternative worth considering: the Megabus Gold which costs around £50, roughly 23:00 to 07:15 the next morning.

You might also want to know that flying (especially from London City Airport with views over London) and taking the train during the day (with preferably a seat on the right-hand side for the part between Newcastle and Edinburgh) are the most scenic.

As someone who does this route maybe twice a month my preferred options are as follows:

1. Fly. If I am in a rush and require to be in Edinburgh early or in a short amount of time then I fly from London City Airport to Edinburgh with British Airways. The flight time is roughly an hour and I can be at the City Airport 20 minutes before take off with no security or boarding issues. The check in is quick as is security and boarding as this is a smaller airport catered for business travel. Access to City Airport is easier for me than Heathrow as I am based in the East End and the DLR is very efficient from Bank, Tower Gateway or Stratford on the London Underground. The quiet and more civilised nature of City Airport suites me better than Heathrow. The flight is pleasant and never full with amazing views of London from take off. The flight usually goes through the centre of England and on clear days you can see both the North Sea and the Irish sea at the same time if you look out of adjacent windows. Flybe also offer a service between City airport and Edinburgh but I have never taken that carrier. Once in Edinburgh airport you can either Tram it on the infamous new Edinburgh Tram system (35 minutes+) to the city centre or you can Bus it (30 minutes) or Taxi it (20-25mins). Taxi is usually over £20 on the meter when I have taken it. Overall travel time for me (door to door) is around 3 hours.
2. Train. Train from Kings Cross to Edinburgh Waverley or Haymarket with Virgin East Coast. If I have some time to spend and fancy a pleasant, scenic and quiet journey then I take the train. Kings Cross is very centrally located and easily accessible from anywhere in London and is probably the best looking train station in the UK (my opinion) The train goes via the East Coast and passes through some very scenic countryside and iconic cities. My favourites being Durham (going over the viaduct into Durham station) and Newcastle (crossing the Tyne as you come into Newcastle station). The Northumberland coast is spectacular after Newcastle also with amazing views out to the North Sea as the track hugs the sparse coastline. Make sure you get a seat on the right hand side of the train as this is where all the action is throughout the journey! Train times are between 4h20 and 5h (there maybe the odd 5h+) However you cannot book trains in the UK until 3 months prior to travel so you will have to wait until August to book. Once in Edinburgh you can either get of at Waverley or Haymarket. I always choose Waverley as it is the more central located for me but there is less than 1 mile between the two. Waverley station is literally the centre of Edinburgh so your right in the middle of the action when you get off the train and go up the steps to street level. Overall travel time for me (door to door) is around 5 hours.

The fastest option is by air. There are frequent services from all of London's airports, including the centrally located London City airport. The flying time is about 1 hour. If you are only visiting Edinburgh for a day or less, this is the sensible way to go.

However, Edinburgh airport is not centrally located (there is a tram, but actually it is faster to take the old airport express bus or a taxi) and it takes another 20 minutes or so to get into town. Also if you are not near a London airport, you may spend some time getting to the airport. Security formalities may take another few minutes.

The alternative is to take the train from Kings Cross. The fastest north bound train takes four hours and twenty minutes, although some trains take closer to five hours. On the flip side, Edinburgh Waverley station is in the centre of Edinburgh.

The fastest commercial option is to fly at 1 hour 10 minutes. The train is roughly 5 hours and driving is also roughly 7 1/2+ hours in excellent conditions.

Ryanair, British Air and other airlines provide comparable times. Flights are available from Gatwick, London City, Heathrow, or Stansted.

Privately, you can hire a helicopter and reduce the flight time by about 10 minutes. I have also taken empty leg flights from Havering Airport (east of London).

You can use Google Flights to get the details.

As i was often traveling on that route, i recommend to use plane.

From Stansted it will take you 70 minutes to get to Edinburgh Airport, then you can take bus 35 or 100 ( I recommend 100, as it goes straight to centre). Currently you can take tram as well. Journey from Airport if you take 100 bus, will take you 30 minutes, and you will have bus every 10 minutes.