• Fares are usually lowest 3–8 weeks out on domestic pairs and 2–5 months out internationally; mid-week departures (Tue/Wed) tend to price under weekend flights.
• Compare nearby alternate airports on both ends — a short train or metro hop can cut the fare substantially on busy corridors.
• Plan for roughly 0.9 hours in the air nonstop over 347.6 km; add buffer for connections under 90 minutes.
• Check each carrier's cabin baggage allowance before choosing on price alone — low-cost fares on this pair often exclude checked bags and seat selection.

Writing the CDG ⇄ LHR route guide — first visit takes a few seconds…

Route data: OpenFlights (ODbL). Schedules change — verify with the airline before booking.