Geo.lon

Longitude in decimal degrees, from -180.0 to 180.0, with western longitudes negative.

CurrentfloatOptionalSince 2.0

Field facts

Always send it together with lat, under the same precision and privacy rules.

Where the field sits in a payload, with everything else left out:

{
  "id": "req-1",
  "device": {
    "geo": {
      "lon": -122.4194
    }
  }
}

Dropping the minus sign for western longitudes, which moves a user in the Americas to Asia.

Added in OpenRTB 2.0, and present in the latest snapshot. The table shows how each version's spec text types the field.

Versions	Type in the spec	Required	Deprecated
2.0 to 2.1	float	No	No
2.2	float ne kn	No	No
2.3 to 2.3.1	float	No	No
2.4	float	No	No
2.5 to 2.6-202606	float	No	No