A Simple Guide to Facebook’s Learning Phase

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If you’ve been in the social advertising space for a while, you’re familiar with optimization and A/B testing. As social advertisers, it’s our job to find the best performing ad copy, creative, audience, etc, to reach our KPI goals. However, did you know that by making some of these adjustments on Facebook, it might be affecting your overall performance? Making even what may be a small change to an ad, ad set or campaign on Facebook could slow your performance due to Facebook’s “Learning Phase.” 

Table of Contents

What is the Learning Phase?

The learning phase occurs when you create a new ad set or make a significant change to an existing ad set or ad. During this phase, Facebook’s algorithm is trying to determine the best way to deliver your ad set. For this reason, it’s important to note that performance has not yet stabilized. Since ad delivery is inefficient, ad sets are less stable and usually have a higher CPA. Therefore, a smaller share of budget spent in the learning phase typically results in a higher share of budget spent on stable performance and lower CPA. In other words, make the best use of your budget by getting out of the learning phase as fast as possible!

The learning phase ends once performance stabilizes and Facebook has received 50 optimization events over a 7-day period. If seven days have elapsed since a significant edit and an ad set has still not exited the learning phase, the Delivery column reads “Learning Limited.”

FB learning Phase - Screenshot 1 FB learning Phase - Screenshot 2

What is a significant change that results in the Learning Phase?

Facebook is somewhat vague as to what their definition of a “significant” change is. However, the following is a list of edits that will put an ad/ad set into the learning phase:


  • Budget (depending on magnitude)
  • Bid amount (depending on magnitude)
  • Bid strategy


  • Any change


  • Targeting
  • Placement
  • Optimization event
  • Adding new creative
  • Bid strategy
  • Bid amount (depending on magnitude)
  • Budget (depending on magnitude)
  • Pausing for over 7 days

You’ll notice in the list that when it comes to changing the budget at either the campaign or ad set level, Facebook will put it in a learning phase “depending on the magnitude.” With our clients, we try to start with small changes and then work up from there to try and avoid the learning phase as much as possible.

What does this mean for you as an advertiser?

Since the learning phase results in unstable ad delivery and a higher CPA, you want to get out of it as quickly as possible. Why? Let’s take a look at an example from one of our clients.

Our client wanted to test the impact of doing weekly ad refreshes. CPL had dropped 21% and lead volume increased 20% in the 3 months leading up to this test so the goal was to see if we could get the CPL even lower.

In the chart below, you’ll notice that when the weekly ad rotation started, in late November, the frequency of learning phases increased (yellow shading.) At the same time, CPL started increasing (blue line) and leads decreased (purple line.) Each time new ads were added, they entered a new learning phase causing instability and inefficiency. The effect of continual learning phases compounded over time and didn’t stabilize until the end of February when we shifted to bi-weekly refreshes.

Therefore, when it comes to making optimizations at the ad or ad set level, be aware of the learning phase. Let Facebook’s algorithm go to work before making an immediate adjustment to try and improve performance. 

Of course, every situation is unique and we would recommend doing a cost/benefit analysis to determine if it is worth going into the learning phase or not. If you believe that making an adjustment that results in the learning phase will generate more of the results that you want and outweighs the time and money spent in the learning phase, then it may be more beneficial to make the adjustment. 

Tips to Get Out Of The Learning Phase Faster

Tip #1: Avoid editing an ad set or ad until it has exited the learning phase.

By making additional edits while your ad or ad set is still in the learning phase, it’s prolonging the process. Remember, you want to make the best use of your ad budget by spending the majority of it outside of the learning phase. If you have multiple edits to make, batching them all at once ensures that learning is only reset one time.

Tip #2: Consolidate Ad Sets

When running too many ad sets at once, each ad set delivers less often. This means that fewer ad sets exit the learning phase and more budget is spent before the delivery system has fully optimized performance. By consolidating ad sets, you are increasing the volume of conversions for the ad set. This helps to reach Facebook’s threshold of 50 conversions needed to exit the learning phase. 

Tip #3: Make Small Incremental Changes

Some changes, such as small adjustments to the budget amount or bid amount at the campaign or ad set level won’t trigger the learning phase. Therefore, we recommend making small, incremental changes over time. Keep in mind which changes trigger the learning phase and try to break optimizations into smaller changes. It isn’t always possible to avoid the learning phase, however, care should be taken to avoid it wherever possible.

Overall, it is important to keep in mind that the learning phase is a time of instability and underperformance. Facebook’s algorithm is testing a variety of ways to deliver your ads and ad sets, which contributes to a higher CPA. Therefore, the best time to spend your budget is outside of the learning phase to gain more results at a lower CPA. The main takeaway is the less time you spend in the learning phase, the better. If you do have to make changes that will result in the learning phase, try and batch all the changes at once to reduce the number of times the account will be in that phase. 


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