Toloka documentation

Starting and stopping a task pool

You can start a pool if:

  1. You uploaded tasks into it.

  2. You have enough money in your account to pay for the pool tasks, including the overlap.

To start the pool, click on the pool page or in the list of pools on the project page.

A started pool has the status “Open”. When all pool tasks are completed, the pool automatically switches to the “Closed” status.

To stop assigning the pool tasks before all of them are completed, click on the pool page or in the list of pools on the project page.


New tasks can be uploaded to an open or closed pool.

What's next


I created a project and a pool, but the Next button doesn't work or the preview shows a blank screen.

Toloka lets you know that something is wrong with the project. The blank screen often appears when there are errors in the task interface, including the JavaScript code. The Next button may be disabled if the output specification lacks some field or contains invalid values, or if, for example, you configured validation for a nonexistent field in JavaScript.

What overlap should I set?

Overlap defines how many Tolokers complete the same pool task.

The best overlap is an overlap that provides satisfying quality of results. For most tasks that are not reviewed, overlap from “3” to “5” is enough. If the tasks are simple, overlap of “3” is likely to be enough. For tasks that are reviewed, set overlap to “1”.

Can I change overlap after the pool is started?

Yes. Open edit mode for the pool and set a new overlap value. You don't need to restart the pool. Updating the settings is usually fast, but if there are many tasks, it may take several minutes.

With dynamic overlap, is it possible that the pool will close before the tasks for minimal overlap run out? The overlap increased, but the pool is closed, and I need to start it manually.

Yes, this might happen. You must set an adequate pool closing interval.