Please be aware that Istanbul has multiple airports and that these results are for all airports serving the city.
The best month to fly between Istanbul and Izmir is January and the most expensive month to fly is May. (Average prices, based on 389 datapoints.)
The best day to arrive at Istanbul is Thursday and it would be best to avoid Saturday, as prices are on average 176.5% higher than on Thursday. (Average prices, based on 363 datapoints.)
The cheapest airline flying from Istanbul to Izmir is Pegasus Airlines. They are 27% cheaper than Turkish Airlines. (Average prices, based on 410 datapoints.)
The best time to fly is at around 20. (Average prices, based on 506 datapoints.)