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prices we've seen · United States fares · USD

Flights from Boston (BOS) to San Francisco (SFO)

  • One way from $142
  • Round trip from $306
  • Nonstop on 9 of 9 dates
  • Fastest 6h 44m
  • 6 airlines

The cheapest one-way fare from Boston (BOS) to San Francisco (SFO) we have seen is $142 USD, departing Dec 15, 2026 (seen Nov 4, 2026): Alaska Airlines AS 389, 1 stop, 30h 33m.

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Prices are the fare alone; the seller shows the bag and fare rules.

Cheapest by month

Checked Nov 11

Pick a month to search the day its cheapest fare leaves.

  1. Nov 2026$251
  2. Dec 2026$142
  3. Jan 2027—
  4. Feb 2027—
  5. Mar 2027—
  6. Apr 2027—
  7. May 2027—
  8. Jun 2027$267

Cheapest days to fly one wayCheapest round trips

Each day's cheapest fare we've seen, nonstop and with stops. Cheapest first.

We may earn a commission from the seller · How we rank

  1. TueDec 15

    18:13

    30h 33m1 stop

    21:46+1

    Cheapest$142 USD

    Alaska Airlines AS 389 · seen Nov 4

    Go to seller — $142

  2. FriDec 18

    11:45

    11h 50m1 stop

    20:35

    $146 USD

    Southwest Airlines WN 813 · seen Nov 10

    Go to seller — $146

  3. MonDec 7

    16:56

    9h 33m1 stop

    23:29

    $150 USD

    Alaska Airlines AS 358 · seen Nov 10

    Go to seller — $150

  4. TueDec 15

    19:40

    6h 46mNonstop

    23:26

    $164 USD

    JetBlue B6 733 · seen Nov 4

    Go to seller — $164

  5. FriDec 18

    10:37

    6h 46mNonstop

    14:23

    $165 USD

    JetBlue B6 2233 · seen Nov 10

    Go to seller — $165

  6. MonDec 7

    19:40

    6h 46mNonstop

    23:26

    $168 USD

    JetBlue B6 733 · seen Nov 10

    Go to seller — $168

  7. SatDec 19

    05:45

    11h 48m1 stop

    14:33

    $227 USD

    United UA 1734 · seen Nov 10

    Go to seller — $227

  8. MonNov 16

    06:15

    6h 44mNonstop

    09:59

    $251 USD

    JetBlue B6 633 · seen Nov 8

    Go to seller — $251

  9. ThuNov 19

    07:55

    6h 50mNonstop

    11:45

    $286 USD

    JetBlue B6 133 · seen Nov 9

    Go to seller — $286

  10. SatNov 28

    20:59

    6h 45mNonstop

    00:44+1

    $342 USD

    JetBlue B6 733 · seen Nov 10

    Go to seller — $342
Show 4 more fares

  1. WedNov 11

    20:40

    6h 45mNonstop

    00:25+1

    $361 USD

    JetBlue B6 333 · seen Nov 10

    Go to seller — $361

  2. SatDec 19

    06:00

    6h 51mNonstop

    09:51

    $386 USD

    United UA 2441 · seen Nov 10

    Go to seller — $386

  3. SunNov 29

    08:00

    55h 15m3 stops

    12:15+2

    $401 USD

    Porter PD 2938 · seen Nov 10

    Go to seller — $401

  4. SunNov 29

    07:10

    6h 49mNonstop

    10:59

    $462 USD

    United UA 1023 · seen Nov 10

    Go to seller — $462

The cheapest round trips we've seen on this route, on any dates, cheapest first.

We may earn a commission from the seller · How we rank

  1. 22 nightsDec 15 – Jan 6

    08:25

    SFO

    Cheapest$242 USD

    Southwest Airlines WN 802 · 2 stops · 26h 32m in all, both ways · seen Nov 4

    Go to seller — $242

  2. 3 nightsDec 10–13

    07:00

    SFO

    $306 USD

    Alaska Airlines AS 459 · 2 stops · 19h 35m in all, both ways · seen Nov 6

    Go to seller — $306

  3. 3 nightsDec 4–7

    18:13

    SFO

    $306 USD

    Alaska Airlines AS 389 · 2 stops · 25h 51m in all, both ways · seen Nov 10

    Go to seller — $306

  4. 3 nightsDec 4–7

    11:45

    15:33

    $311 USD

    JetBlue B6 2233 · Nonstop · 12h 23m in all, both ways · seen Nov 10

    Go to seller — $311

  5. 3 nightsDec 10–13

    19:40

    23:26

    $316 USD

    JetBlue B6 733 · Nonstop · 12h 26m in all, both ways · seen Nov 6

    Go to seller — $316

  6. 22 nightsDec 15 – Jan 6

    19:40

    23:26

    $317 USD

    JetBlue B6 733 · Nonstop · 12h 20m in all, both ways · seen Nov 4

    Go to seller — $317

  7. 31 nightsDec 4 – Jan 4

    07:00

    SFO

    $340 USD

    Alaska Airlines AS 459 · 2 stops · 20h 12m in all, both ways · seen Nov 7

    Go to seller — $340

  8. 31 nightsDec 4 – Jan 4

    15:45

    19:32

    $383 USD

    JetBlue B6 333 · Nonstop · 12h 21m in all, both ways · seen Nov 7

    Go to seller — $383

  9. 12 nightsDec 25 – Jan 6

    05:51

    SFO

    $389 USD

    American Airlines AA 947 · 2 stops · 22h 28m in all, both ways · seen Nov 4

    Go to seller — $389

  10. 13 nightsDec 24 – Jan 6

    20:05

    SFO

    $393 USD

    JetBlue B6 993 · 3 stops · 38h 32m in all, both ways · seen Nov 4

    Go to seller — $393
Show 4 more fares

  1. 13 nightsDec 24 – Jan 6

    07:30

    11:25

    $446 USD

    United UA 1023 · Nonstop · 12h 39m in all, both ways · seen Nov 4

    Go to seller — $446

  2. 12 nightsDec 25 – Jan 6

    07:30

    11:25

    $465 USD

    United UA 1023 · Nonstop · 12h 30m in all, both ways · seen Nov 4

    Go to seller — $465

  3. 6 nightsMar 15–21

    19:41

    23:36

    $476 USD

    JetBlue B6 1833 · Nonstop · 12h 43m in all, both ways · seen Nov 8

    Go to seller — $476

  4. 30 nightsDec 19 – Jan 18

    06:00

    09:51

    $574 USD

    United UA 2441 · Nonstop · 12h 25m in all, both ways · seen Nov 10

    Go to seller — $574

Compare other routes

Compared with Boston → San Francisco: $142 one way (Dec 15).

The way back

Other places from Boston

Every route from Boston →

To San Francisco from other cities

Every route to San Francisco →

Airlines seen on this route

  • American Airlines
  • Alaska Airlines
  • JetBlue
  • Porter
  • United
  • Southwest Airlines

Marketing carriers; the operating airline is shown by the seller.

Boston to San Francisco in numbers

  • By month, Dec 2026 is the cheapest we've seen at $142 USD and Jun 2027 the most expensive at $267 USD — a spread of 88%.
  • Nonstop fares were seen on 9 of the 9 departure dates; carriers seen: American Airlines, Alaska Airlines, JetBlue, Porter, United, Southwest Airlines.
  • BOS serves Boston, United States; SFO serves San Francisco, United States.
  • San Francisco runs 3 hours behind Boston.

Questions

What is the cheapest fare from Boston (BOS) to San Francisco (SFO)?

The cheapest one-way fare from Boston (BOS) to San Francisco (SFO) we have seen is $142 USD, departing Dec 15, 2026 (seen Nov 4, 2026): Alaska Airlines AS 389, 1 stop, 30h 33m.

Is there a nonstop flight from Boston (BOS) to San Francisco (SFO)?

Nonstop fares were seen on 9 of the 9 departure dates; carriers seen: American Airlines, Alaska Airlines, JetBlue, Porter, United, Southwest Airlines.

Which month is cheapest to fly from Boston (BOS) to San Francisco (SFO)?

By month, Dec 2026 is the cheapest we've seen at $142 USD and Jun 2027 the most expensive at $267 USD — a spread of 88%.

How old is this price?

It is the cheapest fare we've seen for that date; the date beside it is the day it was seen, or our last check. We look again at least once a day for the routes people search, and stop showing a route's prices two days after our last look. The seller's page shows the price right now.

How does a2bflight rank results?

By price and duration only; commission never enters the order. Cheapest means cheapest among the fares we've seen for this route. A click that books may earn a2bflight a commission from the seller; the price you see is the seller's own. See how we rank and what we keep.