Bid Adjustments

Bid adjustments are percentage modifiers that raise or lower your bids for specific devices, locations, times of day, or audiences.

You once tuned a campaign by hand with these. Mobile converting worse than desktop, so you cut mobile bids by a set percentage. A city that always paid off, so you pushed bids there up. Set a plus or minus percentage against a device, a location, a schedule, or an audience, and Google shifts the bid up or down whenever that condition is met.

You still see all of these controls in the interface, and on manual or legacy bidding they do exactly what they say. If you are setting your own bids, they remain a genuine way to lean into what works and pull back from what does not. Here is where it gets confusing: the moment you switch to Smart Bidding, whether Target CPA, Target ROAS, Maximize Conversions, or Maximize Conversion Value, the system already reads device, location, time, and audience for every single auction and prices the bid accordingly.

So be careful stacking them. Under Smart Bidding most manual bid adjustments are ignored or, worse, fight the automation, since Google factors those signals in already. Device is the common exception, and they still matter on manual or legacy bidding, but on a smart strategy most of them are just noise you add by hand.

On Smart Bidding, the machine already saw the signal, so your manual override is mostly talking to itself.