If you're collecting Star Alliance miles — either by flying on one of the 26 Star Alliance member airlines, using a co-branded credit card or transferring points — you might be wondering which program should be your focus.

While which airline is best for you to earn your miles ultimately comes down to the redemption options you intend to use, these are our choices for the best Star Alliance airline to earn miles:

Air Canada.

United Airlines.

Avianca.

Here's why these are our picks for the best miles program in the Star Alliance.

Top Star Alliance airline to earn miles

Most miles collectors will want to earn Star Alliance miles in a program that offers a balance of usability and opportunity for awards in premium cabins. With an eye to both U.S. domestic and international travel, you likely want flexibility in how you use your miles (after all, flexibility is the secret to affordable travel).

Our top Star Alliance carriers to earn miles all offer a solid combination of usability and value for domestic travel within the United States and internationally.

Air Canada

Air Canada is a solid bet if you are looking for great award opportunities within North America, coupled with affordable options for premium cabins when flying long-haul. That's why it's our choice for the top Star Alliance airline to earn miles.

Air Canada's loyalty program, Aeroplan, publishes an award chart, making it easy to understand how many miles flights on partner airlines will cost.

The airline also offers several highly-usable sweet spot redemption opportunities. These include awards within North America starting at 6,000 miles each way and flights to Hawaii starting at 12,500 each way. In addition, business class awards between North America and Europe can be found starting at 60,000 miles each way.

The Aeroplan program also features one of the most robust sets of non-alliance partners of any Star Alliance airline, allowing you additional flexibility when using your Aeroplan miles.

All of these value opportunities make Air Canada Aeroplan miles worth 1.4 cents each according to NerdWallet valuations.

United Airlines

A familiar name to U.S.-based flyers, United is a great choice to earn miles, especially if you value your miles being highly usable for travel within the U.S. or prioritize cancellation flexibility.

NerdWallet values United MileagePlus miles at 1.2 cents each — about average compared to competitors — partially because United doesn't offer the most attractive award prices. But if you're looking for a program with easily usable miles, United is a great choice.

United wins kudos for flexibility because the airline allows free changes on all non-basic economy tickets within the U.S. or that originate in the U.S. This change fee waiver applies to all United tickets, including award tickets. In addition, United currently waives all change and redeposit fees for award travel, including award travel with an international origin.

Finally, United offers expanded award availability to its MileagePlus members who maintain elite status or hold one of its co-branded United Airlines credit cards other than the $0-annual-fee United Gateway℠ Card.

Avianca

Avianca, with its LifeMiles frequent flyer program, is a mainstay for Star Alliance awards because it doesn't pass fuel surcharges on to any of its partner award redemptions. The program is also a transfer partner with most of the major transferable points programs, including:

American Express Membership Rewards.

Capital One Miles.

Citi ThankYou Points.

The combination of good value awards and the ability to top off your account from multiple transferable points programs is why Avianca earned a spot on our list.

If you book mostly simple one-way or round-trip awards, Avianca LifeMiles' website works well enough. It even includes a calendar view that can help search for award availability. Some routings may require you to try searching for awards by specific carriers, but with a modest effort, the Avianca website is functional for redeeming simple award flights.

The LifeMiles program does come with some downsides. Unless you have activity in your LifeMiles account, your miles will expire after 12 months of inactivity.