Skyscanner compares flight prices from all airlines and deal-websites (Expedia, Travelocity, Orbitz). You can use this to take spontaneous trips or to find good deals on flights (especially if you don't have a specific destination in mind.
Best search options:
1) You can set it to find the month with the cheapest available flights to any desired destination…See more
Elena Avramenko- Co-Founder at PopAppFactory
I like Skyscanner because of the Explore button. You can select a month, countries of destination (e.g. Netherlands -> Anywhere ) and find a greatest deals for this month to go. Moreover you can select one way ticket and catch the best deal to e.g. Rome from Netherlands, but return ticket buy from Florence to Nethrlands and between Rome-Florence travel …See more