Kayak is one of many websites that are always worth checking but, like them all, it’s far from infallible – nor does it search for everything available.
Its search parameters are somewhat restricted by design, and it can only read from certain data feed points in its supplier websites. This means that the booking fees added by some sites are ignored, raising the risk of the final price paid not being that which was originally shown as the cheapest.
It also suffers from some odd quirks; it claims to interrogate QR’s website, yet for sample dates it shows ebookers being the cheapest site for a LHR-SIN itinerary – at £2219.26. It doesn’t show the £25.00 ebookers credit card fee but, more significantly (given the fact that it suggests that it checks QR’s site), the best price is in fact currently on the QR site – just £1844.30 with no fees.
Unfortunately, there’s no replacement for leg (or click)-work.