From Brighton, reach Gatwick with frequent Southern or Thameslink trains in around 30 minutes

https://www.scribd.com/document/1077066259/Heathrow-to-Gatwick-Airport-Transfers-Coach-Taxi-or-Train-174457

From Brighton, reach Gatwick with frequent Southern or Thameslink trains in around 30 minutes. Trains are direct, making it an easy option for early flights from the coast.