# Click ID

> A unique value an ad platform adds to the link when someone clicks an ad, so it can match later conversions to that click.

Source: https://datacenter.so/glossary/click-id
Also called: click identifier.

Ad platforms add a long, random value to the landing page address on each ad click: `gclid` for Google Ads, `fbclid` for Meta, `ttclid` for TikTok, `msclkid` for Microsoft Advertising, and others. The platform stores the click under that id.

When you later report a conversion with the same id, from the platform's tag or from your server, the platform can credit the exact campaign, ad set and ad. Click ids are stripped by some redirects and, in some contexts, by Safari's Link Tracking Protection. See [click ids explained](https://datacenter.so/guides/click-ids-explained).

## Related terms

- https://datacenter.so/glossary/gclid
- https://datacenter.so/glossary/fbclid
- https://datacenter.so/glossary/utm-parameters