How do I find the cheapest flights online?

Hi, you probably visited letmebook.com in the past and were expecting me to find the cheapest airfare for you. Unfortunately, I got so many requests per day that I was not able to answer each of them in a reasonable amount of time.

I have decided instead to describe my search strategy here, including the pros and cons of each site, so that you can be sure to find the cheapest airfare each time you travel.

The Basics

There are 3 categories of travel websites.

- Airline websites: These are the websites that belong to the airlines (e.g. aa.com). These sites occasionally have promotions or deals that the customer will not find on other travel sites.

- Travel websites: These are essentially travel agencies on the web (e.g. Expedia). Usually, they buy tickets from consolidators (third parties that buy tickets in bulk but are not allowed to sell directly to the public) and resell them to the public. These sites have deals that combine tickets from more than one airline (e.g. for a trip from Austin to Singapore: Austin to Houston with Continental and Houston to Singapore with Singapore Airlines) that the customer will not find on airline websites.

- Agreggator websites: These are search engines that search both airline and travel websites. Instead of booking you tickets at these websites, the site will redirect you to the seller (the travel site or airline site). These sites are very useful. However, it is important to remember that no aggregator website searches every travel and airline website. In addition, these sites must collect data from the other websites therefore they do not always have the most up-to-date airfares. You CANNOT rely on a single search at an aggregator site to find to cheapest ticket every time.

The Search Strategy

1) Start with these 4 aggregator sites:

- Kayak: This site has different url's for difference countries, i.e.: kayak.co.uk, kayak.es, kayak.fr, etc. Start your search at the ".com" url and then search your local url (if there is one). It is always worthwhile to search the ".com" url because it sometimes has the cheapest airfares even if you are departing from a country other than the US. These initial searches with Kayak will give you a clear idea of the possibilities for your airline ticket. However, Kayak does not work with many low-cost airlines and does not always provide the cheapest airfares.

- Momondo: Momondo has different sites for different countries. However, the only difference between these sites is the language - you will find the same prices on each version of the site. Momondo works with most low-cost airlines, but still misses some good deals because it does not work with some good travel websites (e.g. Travelocity).

- Skyscanner: Like Momondo, Skyscanner has different sites for different countries, but the only difference between the sites is the language. This site is especially useful for trips in Europe because its search results include combinations of low-cost airline tickets. For example, say you want to fly from Sevilla to Budapest. There are no low cost airlines that do this route. Skyscanner.net will list options such as Sevilla to Barcelona for 10 EUR with Clickair and Barcelona to Budapest for 7 EUR with WizzAir. You will have links to each of the options. You may have to stop over somewhere for a long time, but it could save you a lot of money.

- Airfarewatchdog: This is a very useful website to find cheap flights. These guys manually check for the best airfares and let you know when they are cheap. They also post airline promotions and discounts on their website.

There are many other aggregator sites. However, I believe that these four are the best to start with. Click here to see more aggregator sites.

2) After your initial search with the aggregator sites you should search travel websites. Here are some good sites:

- Expedia: This site has many different versions depending on your country of origin. I suggest that you look for the airfare in both your country's Expedia website (if your country has one) and the worldwide version (the “.com” one). The results may be different and the prices may differ as well. The “.com” version does not charge a booking fee and it accepts credit cards from many countries.

- Travelocity: Sometimes this site lists good combinations of flights (like 3 stop-overs) that makes the airfare significantly cheaper than the options in other sites. Travelocity has the option to search with flexible travel dates, but this option is only available for flights from the US or Canada. Travelocity also has many different versions depending on your country of origin. I recommend that you look for the airfare in both your country's Travelocity website (if your country has one) and the worldwide version (the “.com” one). The results may be different and the prices may differ as well. The “.com” version does not charge a booking fee and it accepts credit cards from many countries.

- Orbitz and Cheaptickets: These sites give very similar search results. They both allow you to search with flexible travel dates for flights from the US and Canada. They are usually very good sites to check if you are flying from North America, Europe and Asia, but unfortunately, they do not accept credit cards from all countries.

- Vayama: This is a very interesting site and has a nice search interface. This is a good site to check if you are looking for an international one-way ticket or an international multiple destinations ticket. In addition, if you are looking for a business class ticket, I found that this site usually has very good deals. Unfortunately, they do not accept credit card from all countries.

- Airfare: This is another great site that is worth checking out. It accepts credit cards from many countries around the world. It is especially worth checking here if you are looking for an international one-way ticket. In addition, they sometimes offer deals in which you must book that flight before you know what airline you will be flying with (you will find out the airline immediately after you book). These deals are usually cheaper than other options.

- Priceline: This site only has flights departing from US airports. It usually has the same options as the airline websites. However, it is checking this site because sometimes it has the best deals. Moreover, if you are flexible about your travel dates and the airline you fly with, this site lets you bid a the price for the ticket. Therefore, you can get a much cheaper price than on any other travel websites. Priceline.com does not show low-cost airline tickets.

- Hotwire: This site only has flights departing from US airports. It allows you to search with flexible travel dates for flights. Sometimes this site offers deals in which you find out the airlines, hours, and number of stops right after you book. These deals are usually cheaper than other options. Hotwire.com does not show low-cost airline tickets.

- Cheapair: This is usually has good prices and allows you to search with flexible dates. In addition, it will automatically lists flights to airports near your destination airport if they are cheaper. It works worldwide as long as your flight is from, to or through the United States. It accepts credit cards from many countries. However, they charge a $9.95 processing fee that may sometimes make the final price more expensive than a different site.

- CheapOair and Onetravel: If you have more time (and patience!), you can check these two sites also. They usually do not have the cheapest flights, and they list airfares without the tax and fees (which I find very irritating as the final price is always considerably more expensive than what they listed in the search result). However, these sites occassionaly have good deals, especially for international tickets. These websites let you look for flights departing from any airport in the world, but only accepts credit cards from the US, Canada and India. CheapOair.com and Onetravel.com do not show low-cost airline tickets.