**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][1]), but Edinburgh Airport is not ([35 min by the tram][2] or [30 min by the slightly faster Airport 100 bus][3], or [25 min in light traffic][4] 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][5], 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][6] 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][7], takes 47 minutes from Liverpool Street.

**By train**, the fastest is with the East Coast 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][8] 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.

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][9] 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.


  [1]: http://www.londoncityairport.com/
  [2]: http://www.edinburghairport.com/transport-links/trams
  [3]: http://www.edinburghairport.com/transport-links/buses-and-coaches
  [4]: http://www.edinburghairport.com/transport-links/travel-into-edinburgh
  [5]: http://www.londoncityairport.com/travelandbooking/page/check-in
  [6]: https://www.heathrowexpress.com/
  [7]: http://www.stanstedairport.com/to-and-from-the-airport/train/to-and-from-london-by-train/
  [8]: https://www.sleeper.scot/route-destinations/caledonian-sleeper-route
  [9]: http://www.megabusgold.com/