Ad Rotation

Ad Rotation is a campaign-level setting in Google Ads that controls how Google distributes impressions among multiple ads within the same ad group. The two options are “Optimize” (Google favors the best-performing ad) and “Do not optimize” (ads are shown more evenly regardless of performance).

Key Takeaways

• Two rotation settings: “Optimize” (default, recommended) and “Do not optimize” (even rotation)
• “Optimize” lets Google favor the ad with the highest expected performance per auction
• “Do not optimize” distributes impressions more evenly for manual testing
• With Responsive Search Ads, rotation matters less since Google optimizes combinations within each RSA
• Smart Bidding campaigns override rotation settings — Google optimizes automatically

What Is Ad Rotation

Ad Rotation determines how Google selects which ad to show when an Ad Group contains multiple ads. Since Google recommends having 2-3 RSAs per ad group, the rotation setting governs the competition between those ads.

Setting	Behavior	Best For
Optimize (default)	Google shows the ad expected to perform best for each auction, considering query, device, location, and user signals	Most accounts; maximizes performance
Do not optimize	Google distributes impressions roughly evenly across all ads for an indefinite period	Manual A/B testing; gathering equal data

Historically, Google offered additional options like “Optimize for conversions” and “Rotate evenly for 90 days, then optimize.” These were consolidated into the current two options.

How It Works

Ad rotation is configured at the campaign level:

1. Navigate to your campaign settings in the 2026 Google Ads interface
2. Find “Ad rotation” under additional settings
3. Select your preference — Optimize or Do not optimize
4. Save — the setting applies to all ad groups within that campaign

How “Optimize” works in practice:

• Google enters all eligible ads from the ad group into a prediction model
• For each auction, Google estimates which ad is most likely to achieve the best outcome (clicks for maximize clicks strategies, conversions for conversion-focused strategies)
• The predicted best ad is shown
• Over time, the highest-performing ad receives the majority of impressions while lower performers are shown less frequently

How “Do not optimize” works:

• Google distributes impressions across all active ads without performance-based weighting
• Each ad receives a roughly equal share of impressions
• The distribution is not perfectly even (some variation occurs due to auction dynamics) but is significantly more balanced than the optimize setting
• This setting runs indefinitely — unlike the old “rotate evenly for 90 days” option

Practical Example

A SaaS company tests two Responsive Search Ads in a single ad group. They run both rotation settings for 30 days each:

Phase 1: “Do not optimize” (30 days) — data collection

Ad	Impressions	Clicks	CTR	Conversions	Conv. Rate	CPA
RSA A (benefit-focused)	8,200	492	6.0%	22	4.5%	$89
RSA B (urgency-focused)	8,400	420	5.0%	18	4.3%	$93
Total	16,600	912	5.5%	40	4.4%	$91

Both ads received roughly equal impressions, providing a clean comparison. RSA A outperforms on CTR and conversion rate.

Phase 2: “Optimize” (30 days) — performance maximization

Ad	Impressions	Clicks	CTR	Conversions	Conv. Rate	CPA
RSA A (benefit-focused)	13,800	883	6.4%	42	4.8%	$83
RSA B (urgency-focused)	2,800	140	5.0%	5	3.6%	$112
Total	16,600	1,023	6.2%	47	4.6%	$85

With “Optimize,” Google shifted 83% of impressions to RSA A, the stronger performer. Result:

• 7 additional conversions (17.5% increase)
• CPA reduced from $91 to $85 (6.6% improvement)
• Total clicks increased by 12%

The “Optimize” phase outperformed because Google concentrated budget on the proven winner while still showing RSA B occasionally to verify the performance gap.

Why It Matters

Ad rotation strategy depends on your current priority. If you are actively testing new ad copy and need statistically valid data, “Do not optimize” ensures each ad gets a fair share of impressions. Once you have identified a clear winner, switching to “Optimize” lets Google maximize performance by favoring that winner.

In practice, with the shift to Responsive Search Ads, the rotation setting has become less critical than it was during the Expanded Text Ad era. Since each RSA already contains multiple headline and description combinations that Google optimizes internally, the within-ad optimization is often more impactful than the between-ad rotation. The most effective approach for most accounts is to leave rotation on “Optimize,” create 2-3 diverse RSAs per Ad Group testing genuinely different value propositions, and use the asset performance report within each RSA to refine individual headlines and descriptions.