At what age can a baby sleep through the night?

What the evidence says

There's no single age when babies suddenly sleep through the night, because researchers define it differently. In one detailed year-long study of infants, the most common ages for babies to first sleep through were 2 to 3 months if you count a shorter stretch (midnight to 5am or 8 hours total), or closer to 4 to 5 months if you use a more realistic definition like 10pm to 6am.

Even after infants reach these milestones, waking up briefly during the night is completely normal. Research shows infants under 12 months typically stir several times a night, and about 20 to 30 percent of babies continue to have noticeable night wakings through their first two years.

Pediatric guidance also reminds parents that a 'good sleeper' at a young age is a baby who wakes but can settle back down on their own, not one who never wakes at all. By around 12 months, many babies can sleep at least 5 hours continuously, but every baby's pattern is different, and needing help settling at night is not a sign of a problem.