LinkClean

gad_source

Ad-click identifiers · Google Ads · introduced ~2023

What is gad_source?

What gad_source encodes

Google's auto-tagging system gained a series of gad_* parameters in 2023 as part of the GA4 migration. gad_source is a small numeric code — typically a single digit — that identifies which Google Ads surface generated the click. Community-observed values include 1 (Search Ads), 2 (Display Network), 3 (YouTube), 4 (Discovery / Performance Max), 5 (Shopping).

On its own gad_source carries less attribution power than gclid — but it's used in combination with gad_campaignid and the older gclid to disambiguate where a click came from when Google's downstream analytics joins the data.

Why it appeared recently

GA4 deprecated some of the older referrer-driven source attribution that Universal Analytics relied on. To keep the source/medium dimension populated reliably in GA4, Google started adding gad_source + gad_campaignid to outbound clicks as supplementary first-party tags. They sit alongside the classic utm_* and gclid rather than replacing them.

How LinkClean removes it

Default-on. Same default-on treatment as the rest of the gad_* family. No legitimate non-tracking use of this exact name.

Looks like this in a URL
https://example.com/landing?gad_source=1&gad_campaignid=12345678&gclid=Cj0KCQ
After LinkClean
https://example.com/landing

Frequently asked

Why did Google add gad_source if gclid already existed?

Because GA4 needed first-party source/medium signals that don't rely on the cookie or referrer plumbing Universal Analytics had used. gad_source + gad_campaignid are durable first-party tags that survive cookie restrictions.

What do the gad_source numeric values mean?

Community observation: 1 = Search Ads, 2 = Display Network, 3 = YouTube, 4 = Discovery / Performance Max, 5 = Shopping. Google has not formally documented the mapping.

Will removing gad_source affect what I see?

No. It's read by analytics scripts, not by the destination page.

Clean tracking on iPhone, in one tap.

LinkClean strips ~80 vendor-specific tracking parameters from any link, from any app's share sheet — and preserves functional ones like hl, t (YouTube timestamp), and q (search). No account, on-device.

Download on the App Store