Flying is often cheaper. I've found Eurostar fares jump all over the place. On the other hand, I think most of the inexpensive planes that fly this route have pretty strict carry-on luggage limits, which was one reason we took the train.

In 2026, whether the Eurostar (the "Chunnel" train) is cheaper than flying depends heavily on your booking time and total "door-to-door" costs. While budget airlines like EasyJet often advertise base fares as low as £30, the Eurostar offers standard one-way fares starting around £39-£44 if booked months in advance. The true value of the train emerges when you factor in the "hidden" costs of flying: the £15-£25 train or taxi to the airport, the £25-£40 checked bag fees (which are free on Eurostar for two large bags), and the cost of travel from distant airports like Charles de Gaulle or Stansted into the city centers. Because Eurostar travels directly from St Pancras International to Gare du Nord, you save roughly 3-4 hours of total travel time and avoid high airport transfer fees. For most travelers in 2026, the train is the "smart" financial choice for short hops like London-Paris or London-Brussels, as it provides a more comfortable, central, and environmentally friendly experience for a total price that is often lower than a "cheap" flight once all extras are included.