Transport to London Heathrow for checkin at 4:30

The available options will depend on the exact hotel you're staying at.

If your hotel is near a public bus route then you may be able to catch a bus. Some routes run as frequently as every few minutes, even at that time of day. These buses terminate at the Heathrow Central Bus Station which is a short walk from Terminal 3. You can use the Journey Planner on the Transport for London website to see what options are available (use the destination of Heathrow Central Bus Station to get the best results).

If your hotel is located within the "Heathrow Free Travel Zone" then this bus trip will be free. Even if it's not and you need to pay, this will still be the cheapest option by far.

If your hotel is near a "London Underground" station then you can catch that to the airport - although there's only a very limited number of hotels that meet this criteria (eg, the Hilton Garden Inn Heathrow).

Or obviously you can catch a Taxi or rideshare (Uber) to the terminal, given you are only 1.2 miles away.

Historically the the "Hotel Hoppa" service would have also been an option, however this service no longer runs 24 hours a day. Most routes only start after 5am, which is too late for your departure time.

Another option is to not stay near the airport, but instead stay somewhere near Paddington Station, and catch the Heathrow Express to the airport, which takes only 15 minutes. This will be the most expensive option, but may be a better use of your time than having to spend a night near the airport.