There were fears that thousands of passengers would be delayed after the site stopped allowing people to check-in online on Monday afternoon.
Other travellers also struggled to book tickets for future journeys. Customers writing on Facebook complained that the SAS mobile app was working sporadically.
Early on Tuesday, there were still some problems with the site and the airline advised passengers to arrive extra early for all flights.
But by mid-morning the company promised that all issues had been resolved.
SAS said that the glitches had started when a new feature planned for the site was set to launch. This has now been delayed.
The company insisted that the problems were not linked to any security breach or hacker attack.