Is it cheaper to fly London from Paris or take the Eurostar?

It depends on several factors, including the dates of travel, booking time frame, type of ticket (flexible or restricted), airline or train company, and availability.

Generally speaking, the Eurostar is often more expensive than flying from Paris to London. However, there are certain cases where flying can be more expensive, such as during peak travel seasons or if you book your flight at the last minute. Additionally, if you're flexible with your travel dates and times, you may be able to find cheaper flight options.

To get the best deal, it's advisable to compare prices from different airlines and train companies and book in advance whenever possible. You can use online travel comparison websites or apps to easily compare prices and find the best deals. It's also worth considering whether the convenience and travel time of the Eurostar outweigh the potential cost savings of flying.