What is the most punctual flight time for Miami to Seattle flights?

Generally, flights departing in the morning tend to experience fewer delays. Flights at night have, in the past, seen delays more frequently in comparison.

Which layover airport offers the lowest fares from Miami to Seattle?

Flights via Denver (DEN) offer the lowest average round-trip price of $222.

Which layover airport has the shortest travel time from Miami to Seattle?

Flights connecting via Minneapolis (MSP) have the shortest average one-way travel time: 8h 34m.

What airlines fly to Seattle?

Delta, Alaska Airlines and American Airlines are the top three most popular airlines that fly to Seattle from Miami according to our data. Delta is the first choice among our users, with 49% of people opting to fly with this airline when traveling to Seattle. Keep in mind that there are 8 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.

What day of the week experiences the fewest flight delays on this route?

Tuesday is statistically the day of the week which experiences the fewest number of delays on this flight route. Friday has historically seen more delays on average compared to the rest of the week.

What is the cheapest airline that flies from Miami to Seattle/Tacoma Intl?

Frontier, United Airlines, and American Airlines are the most popular carriers operating from Miami to Seattle/Tacoma Intl

How many flights depart from Miami to Seattle on average per week?

The number of flights available between Miami and Seattle is 40 per week as of November 2025. The most frequent departure day is Thu, with 20% of weekly flights leaving on this day.

How often are flights from Miami to Seattle delayed?

Historically, on average around 20% of flights between Miami and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 163 minutes.

Which airline has the best punctuality record on Miami to Seattle flights?

According to our data, Atlas Air have had the least number of delays on this route over the last 12 months; with no flights being classified as delayed.

How many flights depart from Miami to Seattle on average per day?

5 flights are operational daily from Miami to Seattle as of November 2025. The most popular departure time for this route is 6:00PM, with 100% of flights per day taking off in the evening.

Which layover airport has the shortest connection time from Miami to Seattle?

Minneapolis (MSP) has the shortest average layover time for this route: 0h 50m.

Which airport is the most popular layover for flights between Miami and Seattle?

Denver (DEN) was the most common stop: 40% of momondo users choosing 1-stop flights on this route connected there.

When did momondo last update prices for flights from Miami Airport to Seattle/Tacoma Intl Airport?

Prices for flights from Miami Airport to Seattle/Tacoma Intl Airport are refreshed on a daily basis.

How many operators does momondo search for flights from Miami Airport to Seattle/Tacoma Intl Airport?

There are 6 operators available for flights from Miami Airport to Seattle/Tacoma Intl Airport as of November 2025.

How old do you have to be to fly from Miami Airport to Seattle/Tacoma Intl Airport?

The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Miami Airport to Seattle/Tacoma Intl Airport.

What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

The travel and health documents you'll need for your trip to Seattle/Tacoma Intl Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Seattle/Tacoma Intl Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

$134 Cheap Flights from Miami to Seattle in 2025/26

1 adult

0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

Find the cheapest flights from Miami to Seattle

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

4:01 pm - 11:58 pmMIA-SEA

10h 57m1 stop

8:45 am - 5:46 pmSEA-MIA

6h 01mnonstop

$209Delta

Find Deal

Wed, Dec 24 - Wed, Dec 31

6:30 pm - 11:59 pmMIA-SEA

8h 29m1 stop

7:55 am - 4:50 pmSEA-MIA

5h 55mnonstop

$210Delta

Find Deal

Thu, Dec 4 - Wed, Dec 10

7:05 am - 10:11 amMIA-SEA

30h 06m1 stop

1:25 pm - 5:35 amSEA-MIA

37h 10m2 stops

$212Frontier

Find Deal

Sun, Dec 21 - Sun, Dec 28

7:09 pm - 11:53 amMIA-SEA

19h 44m2 stops

9:45 am - 11:18 pmSEA-MIA

10h 33m1 stop

$216Frontier

Find Deal

Thu, Dec 11 - Mon, Dec 15

7:17 am - 11:15 amMIA-SEA

6h 58mnonstop

8:45 am - 5:34 pmSEA-MIA

5h 49mnonstop

$223Alaska Airlines

Find Deal

Wed, Nov 26 - Thu, Dec 4

6:34 pm - 10:30 pmMIA-SEA

6h 56mnonstop

8:45 am - 5:34 pmSEA-MIA

5h 49mnonstop

$235Hawaiian Airlines

Find Deal

Tue, Dec 9 - Thu, Dec 11

6:34 pm - 10:30 pmMIA-SEA

6h 56mnonstop

8:45 am - 5:34 pmSEA-MIA

5h 49mnonstop

$236Alaska Airlines

Find Deal

Wed, Dec 3 - Wed, Dec 10

7:25 am - 11:22 amMIA-SEA

6h 57mnonstop

9:20 pm - 6:05 amSEA-MIA

5h 45mnonstop

$241Hawaiian Airlines

Find Deal

Thu, Dec 25 - Mon, Dec 29

6:15 pm - 12:59 amMIA-SEA

9h 44m1 stop

8:40 am - 7:51 pmSEA-MIA

8h 11m1 stop

$259United Airlines

Find Deal

Fri, Jan 30 - Tue, Feb 3

11:55 am - 9:00 pmMIA-SEA

12h 05m2 stops

11:59 pm - 10:53 amSEA-MIA

7h 54m1 stop

$264United Airlines

Find Deal

Fri, Dec 5 - Sun, Dec 7

Alaska Airlines flights from Miami to Seattle

Our best Alaska Airlines deals on Miami to Seattle flight tickets

Alaska Airlines

Nov 26

MIA7:17 amMiami

6h 58m

SEA11:15 amSeattle/Tacoma Intl

Dec 4

SEA8:45 amSeattle/Tacoma Intl

5h 49m

MIA5:34 pmMiami

$223

Find similar

Alaska Airlines

Dec 3

MIA6:34 pmMiami

6h 56m

SEA10:30 pmSeattle/Tacoma Intl

Dec 10

SEA8:45 amSeattle/Tacoma Intl

5h 49m

MIA5:34 pmMiami

$236

Find similar

Alaska Airlines

Dec 22

MIA7:25 amMiami

6h 57m

SEA11:22 amSeattle/Tacoma Intl

Dec 30

SEA9:20 pmSeattle/Tacoma Intl

5h 45m

MIA6:05 amMiami

$239

Find similar

Frontier flights from Miami to Seattle

Our best Frontier deals on Miami to Seattle flight tickets

Frontier

Dec 21

MIA7:05 amMiami

30h 06m

1 stop

SEA10:11 amSeattle/Tacoma Intl

Dec 28

SEA1:25 pmSeattle/Tacoma Intl

37h 10m

2 stops

MIA5:35 amMiami

$212

Find similar

Frontier

Dec 11

MIA7:09 pmMiami

19h 44m

2 stops

SEA11:53 amSeattle/Tacoma Intl

Dec 15

SEA9:45 amSeattle/Tacoma Intl

10h 33m

1 stop

MIA11:18 pmMiami

$216

Find similar

Frontier

Dec 21

MIA7:05 amMiami

30h 06m

1 stop

SEA10:11 amSeattle/Tacoma Intl

Dec 28

SEA1:25 pmSeattle/Tacoma Intl

37h 10m

2 stops

MIA5:35 amMiami

$217

Find similar

Fly from

Fly to

Route

Depart

Return

Price

MiamiSeattle

MIA - SEA

MIASEA

Miami

Wed 12/24

4:01 pm-11:58 pm

1 stop10h 57m

Seattle/Tacoma Intl

Wed 12/31

8:45 am-5:46 pm

Nonstop6h 01m

$209

MiamiSeattle

MIA - SEA

MIASEA

Miami

Thu 12/4

6:30 pm-11:59 pm

1 stop8h 29m

Seattle/Tacoma Intl

Wed 12/10

7:55 am-4:50 pm

Nonstop5h 55m

$210

MiamiSeattle

MIA - SEA

MIASEA

Miami

Sun 12/21

7:05 am-10:11 am

1 stop30h 06m

Seattle/Tacoma Intl

Sun 12/28

1:25 pm-5:35 am

2 stops37h 10m

$212

MiamiSeattle

MIA - SEA

MIASEA

Miami

Thu 12/11

7:09 pm-11:53 am

2 stops19h 44m

Seattle/Tacoma Intl

Mon 12/15

9:45 am-11:18 pm

1 stop10h 33m

$216

MiamiSeattle

MIA - SEA

MIASEA

Miami

Wed 11/26

7:17 am-11:15 am

Nonstop6h 58m

Seattle/Tacoma Intl

Thu 12/4

8:45 am-5:34 pm

Nonstop5h 49m

$223

MiamiSeattle

MIA - SEA

MIASEA

Miami

Tue 12/9

6:34 pm-10:30 pm

Nonstop6h 56m

Seattle/Tacoma Intl

Thu 12/11

8:45 am-5:34 pm

Nonstop5h 49m

$235

MiamiSeattle

MIA - SEA

MIASEA

Miami

Wed 12/3

6:34 pm-10:30 pm

Nonstop6h 56m

Seattle/Tacoma Intl

Wed 12/10

8:45 am-5:34 pm

Nonstop5h 49m

$236

MiamiSeattle

MIA - SEA

MIASEA

Miami

Thu 12/25

7:25 am-11:22 am

Nonstop6h 57m

Seattle/Tacoma Intl

Mon 12/29

9:20 pm-6:05 am

Nonstop5h 45m

$241

MiamiSeattle

MIA - SEA

MIASEA

Miami

Fri 1/30

6:15 pm-12:59 am

1 stop9h 44m

Seattle/Tacoma Intl

Tue 2/3

8:40 am-7:51 pm

1 stop8h 11m

$259

MiamiSeattle

MIA - SEA

MIASEA

Miami

Fri 12/5

11:55 am-9:00 pm

2 stops12h 05m

Seattle/Tacoma Intl

Sun 12/7

11:59 pm-10:53 am

1 stop7h 54m

$264

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from Miami to Seattle

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

Prices

Airlines

Delays

Layovers

Other information

What is the cheapest month to fly to Seattle?

In general, February is the cheapest month to fly from Miami to Seattle. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $299. If you don’t want to visit Seattle in February, then you should wait until September to fly from Miami, when ticket prices are also cheap, with an average price of $299.

What is the cheapest day to depart on your flight to Seattle?

On average, the least expensive day to fly to Seattle from Miami is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as $332. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Monday is the most expensive day to depart from Miami because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $496.

What is the cheapest time of day to depart on your flight to Seattle?

Flying to Seattle from Miami at noon is the least expensive time of day to depart. momondo users have found prices as low as $338 when looking at flights departing at noon. Flights to Seattle are more costly in the morning, with an average ticket price of $451. Departure times in the morning fall within the peak daily travel times, which is why tickets can be more expensive.

What is the cheapest Miami to Seattle/Tacoma Intl flight route?

Fly from Miami to Seattle/Tacoma Intl for the best Miami - Seattle/Tacoma Intl flight prices

How far in advance should I book a flight to Seattle?

You are more likely to see cheaper flights to Seattle from Miami when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around $345 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from Miami for as low as $279 on momondo.

What cabin class options are available on Miami to Seattle/Tacoma Intl flights?

There are 4 cabin classes available to choose from on Miami to Seattle/Tacoma Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Miami to Seattle flights?

No. A direct flight is the cheapest option for a flight between Miami to Seattle.

How have Miami to Seattle flight prices changed over time?

As of November 2025, prices for Miami to Seattle flights are approximately 11% more expensive when compared to flights at the same time last year.

When to book flights from Miami to Seattle

Are you open to changing your travel dates? Check out the ideal times to fly from Miami to Seattle according to our flight data. Find out which month and days have the cheapest flights.

Estimated round-trip price

Cheap Miami to Seattle (MIA to SEA) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Miami to Seattle

Best Price Found	$228
Fastest flight time	6h 30m
Direct flights	Every day
Airports in Seattle	1 airport

The best one-way flight to Seattle from Miami in the past 72 hours is $228. The best round-trip flight deal from Miami to Seattle found on momondo in the last 72 hours is $317.

The fastest flight from Miami to Seattle takes 6h 30m

Direct flights go from Miami to Seattle every day.

There is 1 airport near Seattle: Seattle/Tacoma Intl (SEA)

Search flight deals

How far is Miami to Seattle/Tacoma Intl by plane?
Seattle/Tacoma Intl is 2729.6 mi away from Miami. By plane, this route typically takes 6h 50m.
When did momondo last update prices for flights from Miami Airport to Seattle/Tacoma Intl Airport?
Prices for flights from Miami Airport to Seattle/Tacoma Intl Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Miami Airport to Seattle/Tacoma Intl Airport?
There are 6 operators available for flights from Miami Airport to Seattle/Tacoma Intl Airport as of November 2025.
How old do you have to be to fly from Miami Airport to Seattle/Tacoma Intl Airport?
The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Miami Airport to Seattle/Tacoma Intl Airport.
What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?
The travel and health documents you'll need for your trip to Seattle/Tacoma Intl Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Seattle/Tacoma Intl Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from Miami to Seattle?
Based on momondo bookings for flights between Miami and Seattle, the leading plane model is Airbus A321neo, making up 48.37% of the total bookings. Other popular models include Boeing 737 MAX 9 with 25.23%, Boeing 737-900 Passenger/BBJ3 (winglets) with 10.98%, and Boeing 737 with 5.49%.
What is the most popular airline from Miami to Seattle?
momondo data reveals that the most frequently booked airline on the route from Miami to Seattle is Delta, representing 40% of all bookings. The subsequent popular airlines are American Airlines at 24%, Alaska Airlines at 21%, and Frontier at 7%.

Best airlines flying from Miami to Seattle

Compare and see reviews for airlines that fly from Miami to Seattle with momondo

Airline	Rating	Free Cancellation	Price
Frontier	PriceFrom $108	Free Cancellation	Rating 5.8 3,115 reviews	Search Frontier flights
Hawaiian Airlines	PriceFrom $138	Free Cancellation	Rating 7.8 2,804 reviews	Search Hawaiian Airlines flights
Delta	PriceFrom $196	Free Cancellation	Rating 7.9 8,001 reviews	Search Delta flights
Alaska Airlines	PriceFrom $220	Free Cancellation	Rating 8.0 11,247 reviews	Search Alaska Airlines flights
American Airlines	PriceFrom $257	Free Cancellation	Rating 7.2 11,040 reviews	Search American Airlines flights
United Airlines	PriceFrom $262	Free Cancellation	Rating 7.4 9,007 reviews	Search United Airlines flights

Alaska Airlines Flights From Miami to Seattle
Alaska Airlines flies from Miami to Seattle around 1 time per week, with 11,246 momondo users rating the airline 8.0/10. The cheapest Alaska Airlines deal from Miami to Seattle in the last 72 hours was $220 (round-trip), much lower than the average airfare cost of $370 for Alaska Airlines flights on this route.
Delta Flights From Miami to Seattle
The best Delta deal for Miami to Seattle flight tickets found on momondo in the last 72 hours was $196, round-trip. It should be noted that an average Delta flight deal for this route in this time was higher, at $340 round-trip. Delta operates 4 flights out of Miami into Seattle in an average week, so prices vary by time and availability. 8,001 Delta reviews by users on momondo have scored the airline at 7.9/10.

Tacoma

Leavenworth

SeaTac

Ocean Shores

Renton

Olympia

Lynnwood

Kent

Puyallup

Marysville

Redmond

Tukwila

Lakewood

Federal Way

Fife

Cle Elum

Centralia

Kirkland

Westport

Shoreline

Why use momondo?

Why should I use momondo to find a flight deal from Miami to Seattle?

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Miami to Seattle for you.

Can I find flights from Miami to Seattle with flexible booking policies on momondo?

All flight searches from Miami to Seattle on momondo can be filtered to show those which offer flexible booking policies.

How can momondo help me find flights from Miami to Seattle?

momondo provides multiple filters to help you find the best flight to Seattle from Miami. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

I’m not ready to book a flight from Miami to Seattle right now. Can momondo alert me if prices change?

Of course. momondo tracks the price of Miami to Seattle flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

An easier way to manage your Seattle trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Start using Trips

Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

1 adult

Sat 12/6

Sat 12/13

Email me momondo's favorite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States

Airports servicing Washington

Walla Walla Airport

Bellingham Airport

Wenatchee Pangborn Field Airport

Eastsound Orcas Island Airport

Friday Harbor SPB Airport

Spokane Airport

Kenmore Air Harbor Airport

Pasco Tri Cities Airport

Pullman Moscow Regional Airport

Rosario SPB Airport

Yakima Air Terminal Airport

Popular cities in the United States

Flights to New Yorkfrom $44

Flights to Los Angelesfrom $49

Flights to Miamifrom $49

Flights to Chicagofrom $54

Flights to Orlandofrom $49

Flights to Las Vegasfrom $42

Flights to San Franciscofrom $57

Flights to Washington, D.C.from $49

Flights to Bostonfrom $49

Flights to Atlantafrom $40

Flights to Dallasfrom $59

Flights to Denverfrom $57

Cheap flights from Miami to Seattle from $134

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Miami to Seattle departing on 2/1. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Big names and deals

Big names and deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

Find the cheapest flights from Miami to Seattle

Cheap round-trip flights

Cheap one-way flights

Cheap last minute flights

Cheap direct flights

Alaska Airlines flights from Miami to Seattle

Our best Alaska Airlines deals on Miami to Seattle flight tickets

Frontier flights from Miami to Seattle

Our best Frontier deals on Miami to Seattle flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from Miami to Seattle that are best for you.

See travel insights to Seattle from

How to get the cheapest flight ticket from Miami to Seattle

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Seattle?

What is the cheapest day to depart on your flight to Seattle?

What is the cheapest time of day to depart on your flight to Seattle?

What is the cheapest Miami to Seattle/Tacoma Intl flight route?

Fly from Miami to Seattle/Tacoma Intl for the best Miami - Seattle/Tacoma Intl flight prices

How far in advance should I book a flight to Seattle?

What cabin class options are available on Miami to Seattle/Tacoma Intl flights?

There are 4 cabin classes available to choose from on Miami to Seattle/Tacoma Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Miami to Seattle flights?

No. A direct flight is the cheapest option for a flight between Miami to Seattle.

How have Miami to Seattle flight prices changed over time?

As of November 2025, prices for Miami to Seattle flights are approximately 11% more expensive when compared to flights at the same time last year.

What is the cheapest airline that flies from Miami to Seattle/Tacoma Intl?

Frontier, United Airlines, and American Airlines are the most popular carriers operating from Miami to Seattle/Tacoma Intl

What airlines fly to Seattle?

How often are flights from Miami to Seattle delayed?

Historically, on average around 20% of flights between Miami and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 163 minutes.

What is the most punctual flight time for Miami to Seattle flights?

Generally, flights departing in the morning tend to experience fewer delays. Flights at night have, in the past, seen delays more frequently in comparison.

What day of the week experiences the fewest flight delays on this route?

Tuesday is statistically the day of the week which experiences the fewest number of delays on this flight route. Friday has historically seen more delays on average compared to the rest of the week.

Which airline has the best punctuality record on Miami to Seattle flights?

According to our data, Atlas Air have had the least number of delays on this route over the last 12 months; with no flights being classified as delayed.

Which airport is the most popular layover for flights between Miami and Seattle?

Denver (DEN) was the most common stop: 40% of momondo users choosing 1-stop flights on this route connected there.

Which layover airport offers the lowest fares from Miami to Seattle?

Flights via Denver (DEN) offer the lowest average round-trip price of $222.

Which layover airport has the shortest travel time from Miami to Seattle?

Flights connecting via Minneapolis (MSP) have the shortest average one-way travel time: 8h 34m.

Which layover airport has the shortest connection time from Miami to Seattle?

Minneapolis (MSP) has the shortest average layover time for this route: 0h 50m.

How many flights depart from Miami to Seattle on average per day?

5 flights are operational daily from Miami to Seattle as of November 2025. The most popular departure time for this route is 6:00PM, with 100% of flights per day taking off in the evening.

How many flights depart from Miami to Seattle on average per week?

The number of flights available between Miami and Seattle is 40 per week as of November 2025. The most frequent departure day is Thu, with 20% of weekly flights leaving on this day.

When to book flights from Miami to Seattle

Cheap Miami to Seattle (MIA to SEA) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Miami to Seattle

Best Price Found

Fastest flight time

Direct flights

Airports in Seattle

How far is Miami to Seattle/Tacoma Intl by plane?

When did momondo last update prices for flights from Miami Airport to Seattle/Tacoma Intl Airport?

How many operators does momondo search for flights from Miami Airport to Seattle/Tacoma Intl Airport?

How old do you have to be to fly from Miami Airport to Seattle/Tacoma Intl Airport?

What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

What is the most popular plane model from Miami to Seattle?

What is the most popular airline from Miami to Seattle?

Best airlines flying from Miami to Seattle

Compare and see reviews for airlines that fly from Miami to Seattle with momondo

Alaska Airlines Flights From Miami to Seattle

Delta Flights From Miami to Seattle

Traveling to a place near Seattle?

Why use momondo?

Why should I use momondo to find a flight deal from Miami to Seattle?