# gclid

> Google Ads' click id, added to landing page links by auto-tagging.

Source: https://datacenter.so/glossary/gclid
Also called: Google Click Identifier.

`gclid` (Google Click Identifier) is added to your landing page address when someone clicks a Google ad and auto-tagging is on. GA4 reads it to show Google Ads campaign data, and Google Ads uses it to match conversions to clicks, including conversions you upload later from your own system.

On iOS traffic where Apple's rules limit `gclid`, Google uses `gbraid` and `wbraid` instead. These are aggregate identifiers that cannot tie a conversion to one person ([Google](https://support.google.com/google-ads/answer/10417364)).

If a redirect on your site drops the query string, the `gclid` is lost and Google Ads conversions go missing. Test with `?gclid=test` on each landing page.

## Related terms

- https://datacenter.so/glossary/click-id
- https://datacenter.so/glossary/fbclid
- https://datacenter.so/glossary/enhanced-conversions