About explanations

Explanations give you insights into large changes in your Google Ads account performance. When you see a significant fluctuation in performance for a Search campaign or ad group, explanations help you quickly find out why it happened.

Explanations are currently only available for Search campaigns using manual CPC, enhanced CPC, or target CPA bidding.


  • Save time: Discover why your account performance changed with just a few clicks.
  • All in one place: You no longer have to cross-reference reports, checklists, or other tools—simply compare two date ranges, and explanations for significant performance changes will be provided, if available.
  • Diagnose issues: Get a more accurate and comprehensive view to diagnose possible reasons for changes in your campaign or ad group's performance.

Types of explanations

Explanations can help you learn more about how the following factors might have affected your campaign or ad group performance.

  • Bid changes: How changes to your bids may have affected where and how often your ads showed. 
  • Bid strategy target changes: How changes to ad group, campaign or portfolio level target may have affected your performance. 
  • Bid limit changes: How setting or changing bid limits affects automatic optimization of your bids. Bid limits can prevent Google Ads from adjusting your bids to the amount that best meets your target.
  • Bid strategy changes: How strategy type or portfolio changes may affect performance. Each type of automated bid strategy is designed to help you achieve a specific goal for your business.
  • Bid Modifier changes: How changes to your device bid modifier, location bid modifier, demographic bid modifier, and audience bid modifier may have affected performance.
  • Budget changes: How changes to your budget may have affected how many clicks and impressions your ads received.
  • Budget allocation: How spreading your budget across multiple entities (for example, ad groups) may have affected the performance of other entities.
  • Budget exhaustion rate: How changing your average cost-per-click (CPC) may have caused your budget to run out more quickly or slowly than usual. 
  • Conversions: How changing your conversion actions status or settings may have affected the number of your conversions. Explanations also include data on conversion lag and tag firing frequency to help diagnose your performance changes.
  • Eligibility: How different factors may have affected how often your ads were eligible for traffic (for example, budget exhaustion or pausing an ad group or campaign, when all ads in an ad group were disapproved).  
  • Targeting changes: How changes to location targeting, keywords targeting, keyword status, and adding/removing an audience may affect performance.
  • Auction competitions and search interest: How changes in search volume on Search partners and opt-in/opt-out of Search partners may affect performance.
  • Change history: How changes to your account may have affected your account’s performance.  

How to view explanations in your account

You won’t see explanations if your date range contains today’s date because there may be more data for the day.

View explanations

By default, you’ll see explanations that compare the date range you selected with the previous period of the same length:

  1. Go to your campaign or ad groups page.
  2. Hover over values in your data table that are colored in blue with a dotted line.
  3. You’ll see how this value has changed since the last period.
    For example, if you selected the last 7 days as your date range, you’ll see explanations of how your performance changed from the week before.
  4. Click View explanation to see what caused the change.

Get explanations for custom date ranges

To compare two custom ranges, choose the two time periods you want to compare in the date range selection:

  1. In the upper right corner of your screen, click the down arrow next to the date range.
    Drop Down Menu
  2. Click the toggle next to "Compare", and then select Previous period below it.
  3. Select a time period. Make sure both periods are of equal length and contiguous, or explanations won’t show.
  4. Click Apply.

You’ll see a % change added below the numbers in your performance metrics columns.

Significant changes will be highlighted in blue and have an explanation.

Why you might not see explanations

  • Explanations are only available for Search campaigns using manual bidding, enhanced CPC, or target CPA. You won’t see explanations for Search+, Display, Video, Shopping, or Dynamic Search Ads campaigns.
  • Currently explanations supports clicks, cost, impressions, and conversions only. 
  • Explanations will only be triggered if they meet the volume and change threshold.
  • Explanations are only available for data within the last 90 days.You can still view the % change for more than 90 days, but the explanations window won’t show.
  • Explanations work only for comparisons of equal length and contiguous time periods.

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