What is the difference between OneTimeWorkRequest and PeriodicWorkRequest and what is the minimum interval?

Short answer

OneTimeWorkRequest runs the task only once, while PeriodicWorkRequest runs it periodically and repeatedly, and the minimum interval is 15 minutes to save power.

Explanation

The WorkManager library imposes a minimum of 15 minutes for the PeriodicWorkRequest interval (the constant PeriodicWorkRequest.MIN_PERIODIC_INTERVAL_MILLIS) to avoid draining the device's resources and battery. Periodic tasks also support a flex period that determines when the system may run the task within each repeat cycle according to the specified conditions, and batching system tasks at the same time.

Code example

// A periodic task runs at most once every six hours (the interval is a minimum, not an exact schedule):
val syncRequest = PeriodicWorkRequestBuilder<SyncWorker>(
    repeatInterval = 6,
    repeatIntervalTimeUnit = TimeUnit.HOURS,
    flexTimeInterval = 30, // 30-minute flex window
    flexTimeIntervalUnit = TimeUnit.MINUTES
).build()

WorkManager.getInstance(context).enqueueUniquePeriodicWork(
    "SyncWork",
    ExistingPeriodicWorkPolicy.KEEP,
    syncRequest
)

Common mistakes

• Trying to set repeatInterval to less than 15 minutes, where WorkManager ignores the value and forcibly resets it to 15 minutes as a minimum automatically.

Follow-up questions

• What is the architecture of WorkManager and why is it considered the recommended solution for guaranteed and deferred tasks?

Sources

• Android Developers — Schedule periodic work