(telemetry-pings)=

# Telemetry pings

A *Telemetry ping* is the data that we send to Mozilla's Telemetry servers.

The top-level structure is defined by the {doc}`common ping format <../data/common-ping>`. This is a JSON object which contains:

- some basic information shared between different ping types
- the {doc}`environment data <../data/environment>` (optional)
- the data specific to the *ping type*, the *payload*.

## Ping types

We send Telemetry with different ping types. The {doc}`main <../data/main-ping>` ping is the ping that contains the bulk of the Telemetry measurements for Firefox. For more specific use-cases, we send other ping types.

Pings sent from code that ships with Firefox are listed in the {doc}`data documentation <../data/index>`.

Important examples are:

- {doc}`main <../data/main-ping>` - contains the information collected by Telemetry (Histograms, Scalars, ...)
- {doc}`saved-session <../data/main-ping>` - has the same format as a main ping, but it contains the *"classic"* Telemetry payload with measurements covering the whole browser session. This is only a separate type to make storage of saved-session easier server-side. As of Firefox 61 this is sent on Android only.
- {doc}`new-profile <../data/new-profile-ping>` - sent on the first run of a new profile.
- {doc}`update <../data/update-ping>` - sent right after an update is downloaded.
- {doc}`deletion-request <../data/deletion-request-ping>` - sent when FHR upload is disabled
