# Data collection (deprecated)

:::{important}
Legacy Telemetry collection APIs are now deprecated.
Please use Glean instead.
:::

There are different APIs and formats to collect data in Firefox, all suiting different use cases.

In general, we aim to submit data in a common format where possible. This has several advantages; from common code and tooling to sharing analysis know-how.

In cases where this isn't possible and more flexibility is needed, we can submit custom pings or consider adding different data formats to existing pings.

*Note:* Every new data collection must go through a [data collection review](https://wiki.mozilla.org/Firefox/Data_Collection).

The current data collection possibilities include:

- {doc}`scalars` allow recording of a single value (string, boolean, a number)
- {doc}`histograms` can efficiently record multiple data points
- `environment` data records information about the system and settings a session occurs in
- {doc}`events` can record richer data on individual occurrences of specific actions
- {doc}`Measuring elapsed time <measuring-time>`
- {doc}`Custom pings <custom-pings>`
- {doc}`Experiment annotations <experiments>`
- {doc}`WebExtension API <webextension-api>` can be used in privileged webextensions
- {doc}`User Interactions <user-interactions>` allow annotating hang report pings with information on what the user was interacting with at the time

```{toctree}
:glob: true
:hidden: true
:maxdepth: 2
:titlesonly: true

scalars
histograms
events
measuring-time
custom-pings
experiments
*
```

## Browser Usage Telemetry

For more information, see {ref}`browserusagetelemetry`.

## Version History

- Firefox 61: Stopped reporting Telemetry Log items ([bug 1443614](https://bugzilla.mozilla.org/show_bug.cgi?id=1443614)).