This document describes search telemetry recorded by Toolkit such as search service telemetry and telemetry related to fetching search suggestions.

Other important search-related telemetry is recorded by Firefox and is documented in Telemetry in the Firefox documentation.



Records the search service initialization code on startup. This is typically one of the error values in


Records the number of secure (i.e., using https) OpenSearch search engines a given user has installed


Records the number of insecure (i.e., using http) OpenSearch search engines a given user has installed


Records the number of OpenSearch search engines with secure updates enabled (i.e., using https) a given user has installed


Records the number of OpenSearch search engines with insecure updates enabled (i.e., using http) a given user has installed

Keyed Scalars


Records the WebExtension ID of a search engine where the saved search engine settings do not match the WebExtension.

The keys are the WebExtension IDs. The values are integers:

  1. Associated WebExtension is not installed.

  2. Associated WebExtension is disabled.

  3. The submission URL of the associated WebExtension is different to that of the saved settings.



This histogram records the latency in milliseconds of fetches to the suggestions endpoints of search engines, or in other words, the time from Firefox’s request to a suggestions endpoint to the time Firefox receives a response. It is a keyed exponential histogram with 50 buckets and values between 0 and 30000 (0s and 30s). Keys in this histogram are search engine IDs for built-in search engines and ‘other’ for non-built-in search engines.

Default Search Engine

Telemetry for the user’s default search engine is currently reported via two systems: