> For the complete MongoDB documentation index, see www.mongodb.com/docs/llms.txt

# Online Archive Costs

You incur Atlas Data Federation costs for the following items:

- Amount of data stored and accessed for Online Archive. You are charged on the basis of the gigabytes used and the number of days spent for data storage. The cost varies by the cloud provider and region. To learn more about the pricing for each region, go to the [pricing page](https://www.mongodb.com/pricing), scroll down to the Customize your deployment with tools & services section and click See pricing under Online Archive.

- Amount of archived data processed while querying the Online Archive, and the amount of data transferred and returned when you query your Online Archive. Note that Atlas charges $5.00 per TB of processed data, with a 10 MB minimum processed data per query. You can optionally configure [query limits](https://www.mongodb.com/docs/atlas/data-federation/query/manage-query-limits.md#std-label-adf-manage-query-limits) to control data processing charges for your Online Archive.

To learn more about the consumption-based pricing for Online Archives, see the [pricing page.](https://www.mongodb.com/pricing)

**Important:**

Before querying the archived data, we recommend using the [explain](https://www.mongodb.com/docs/manual/reference/method/cursor.explain/) method to optimize your queries. To calculate the monthly spend and approximate cost based on usage, consider the typical amount of data processed in the [explain results](https://www.mongodb.com/docs/manual/reference/explain-results/) and multiply it by the typical number of queries per month.

To stay abreast of your Online Archive costs, we recommend the following:

- [Configure billing alerts](https://www.mongodb.com/docs/atlas/reference/alert-conditions.md#std-label-billing-alerts) to avoid unexpected usage and charges.

- Monitor the [cost visualization](https://www.mongodb.com/docs/atlas/billing.md#std-label-billing-visualizations) and [invoices](https://www.mongodb.com/docs/atlas/billing.md#std-label-examine-invoices) on your Atlas billing page.

  The federated database instance page for Online Archive displays the amount of data that your federated database instance has processed and returned, and the number of queries run against it. However, it doesn't reflect the cost of your Online Archives, which is available in the Atlas [billing page](https://www.mongodb.com/docs/atlas/billing.md#std-label-atlas-billing) only.