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5 Prebid Timeout Mistakes Publishers Make And How to Fix Them
Ad Optimization

5 Prebid Timeout Mistakes Publishers Make And How to Fix Them

May 22, 2024
May 24, 2024

AdTech space is very sensitive, where even a millisecond of changes wields immense power to your bottom line. This holds true in the terms of Prebid timeout, where only a millisecond change is needed to either skyrocket your revenue or make it fall into the pit.

Optimizing the Prebid timeout to find the sweet spot value is a complicated process, bound with constraints, and needs various considerations. It is challenging, and a lack of proper optimization might lead to mishaps.

In the worst-case scenario, these mistakes might pull you apart from the potential opportunities and plummet your revenue. So, how will you rectify it?

Don’t know! No worries, we have got you covered. Let’s get to the bottom of the problem to know the common Prebid timeout mistakes that publishers make. Also, learn how to fix them with reliable solutions. 

Read on to get more wisdom today!

Understanding Prebid Timeout

Prebid is a leading header bidding solution. After invoking an ad request, the header bidding setup on your website needs a time period to wait for collecting returning bids before calling the ad server. This delay is called Prebid timeout, within which all the demand partners connected to your header bidding setup must return their bids. If not, they will get timed out.

The prebid timeout shouldn’t be either high or low. Higher timeout causes higher page loading times and affects user experience, whereas low Prebid timeout misses potential bids and increases the timeout rate.

Either situation causes revenue loss, affects UX, and decreases the ad yield.  That is why Prebid timeout adjustment and optimization are needed to manage this trade-off so that:

  • You will not miss out on the potential bids with lesser timeout value.
  • Maintain a positive user experience by not setting too long timeout.
  • Increase the overall revenue by balancing the missed revenue opportunities caused by short timeouts and page loading times caused by long timeouts.

The best range to start optimizing your timeout settings is below 1000 milliseconds for internal auction timeout

Common Prebid Timeout Blunders that Publishers Make

While setting or working on finalizing the Prebid timeout values, you might have made mistakes by not considering a few factors. Those factors might seem trivial, but they might have a lasting effect on your revenue. Here, we have shared important factors or mistakes that you might make when setting timeouts. Let’s dig into it.

Using one value for all

No one value fits all scenarios. This phrase suits the Prebid timeout, too. You are finalizing the timeout value after considering metrics like bid performance, bidder responses, and user behavior but keeping one timeout value for all regardless of device (mobile and desktop), demographics, geography, and page context. 

The auction process or ad-serving process differs according to the previous categories, so setting the common value will yield unlikely results that lead to poor user experience and overall revenue. This kind of mistake is often overlooked by publishers while setting Prebid timeout.

Too many bidders in the auction 

Connecting with more bidders gets high CPM for your inventory, increases fill rate, and improves revenue. Yes, it is true until the word “more bidders” has a limit. Suppose you have many bidders bid in your auction and continue to do so without analyzing their performance, its influence on page loading times, revenue contribution, win rate, etc. Then, My friend, you are going off the rails.

The bidders who are inactive and with low win rates in the auction cause only higher page loading times, which will eventually affect the user experience. These bidders cannot return the bids within the time, and they might also prevent other potential bids from reaching the website within time. Therefore, your revenue will be affected to a large extent. 

Timeout trap

The faulty configuration of the Failsafe timeout can lead to a substantial loss of revenue in the Prebid setup. It is a second timeout set on top of the Prebid timeout.

This timeout will be set and activated when Prebid meets with any issues. If a Prebid doesn’t return the bid within the specified timeout due to any technical issues, the Failsafe timeout shuts down the auction and returns a null value to the ad server( mostly GAM). It will prevent Prebid from participating in the auction. This scenario is called a timeout trap.


Failsafe timeout is generally a protective timeout for handling situations when Prebid fails to work. The problem arises when the Failsafe timeout is set equal to or lower than the Prebid timeout. 

Even when a single SSP times out, instead of concluding an auction with one less bidder, the Failsafe timeout triggers and sends no Prebid bids to an ad server. Thus, Prebid will lose the chance to compete with other bids on the ad server. 

Failing to do consistent optimization

The auction dynamics in the ad tech space evolve every minute. The Prebid timeout you set, which is optimal now, will be suboptimal after a week or even a day. It is not a set-it-and-leave-it process. Doing so will only increase the timeout rate and have a negative impact on user experience and ad revenue. 

Delay in fetching dynamic data

To optimize the auction process and get the best price for your inventory, you fetch and feed dynamic data like floor prices and targeting data from Prebid modules into the auctions. 

The computing and insertion of dynamic data start only after when the user invokes the ad request. These dynamic data are vital to help bidders bid based on their and your requirement to increase the CPM

The dynamic data is essential for auction optimization, but its fetching process could delay your Prebid timeout. It might cause a domino effect by delaying the Prebid timeout to miss out on the potential bids, impacting the user experience and eventually reducing revenue. 

Thus, delay in fetching the dynamic data and failing to optimize fetch-timeout is one of the important mistakes that publishers make while optimizing Prebid timeouts. 

How to Fix It? 

Thus far, we have seen the common Prebid timeout mistakes. Now, it’s time to see the solution. 

Optimize timeout based on context and device

Every channel and medium you use to show ads is different, So find optimal timeout that suits different devices. Mobile devices, for instance, have slower network speeds and might need a long timeout, whereas desktops with faster networks will need shorter timeouts.

Content context also plays a major role, which is true according to the experts:

For instance, the page with higher traffic can only hold shorter auction timeouts to maintain user engagement. While some other content can afford longer timeouts, but it could also lose some revenue. Therefore, doing A/B testing is essential to find the right spot in the bell curve of page load times and auction timeouts. Specifically, doing testing page-wise, traffic-wise, and in a more granular way will reap effective results and promising revenue hikes. 

Vet bidders timely

One of the ideal ways to reduce the timeout rate is to vet bidders in a timely manner and replace the inactive ones with potential bidders. 

You can vet them based on their participation frequency, active time, win rate, bid rate, etc, to know the revenue they bring to your table. This way, you can remove and replace the bidder adapter that slows down your website and prevents other potential bidders from responding to your ad request with a new one. 

But in the second case, what if the potential bidder contributing a higher revenue percentage to your ad revenue gets timeout often? It is ideal to do bidder-level optimization to find the reason for the timeout. The reasons can be weak infrastructure, bad CMP configuration, poor auction setup, network quality, etc. Then, rectify the cause to solve the issue. This way, you make sure your revenue opportunities reach you in on time.  

Set higher Failsafe timeout

Optimized Prebid timeout values that generate high revenue will become useless if you badly configure the Failsafe timeout value. But how can you avoid this timeout trap? Simply set a Failsafe timeout higher than the Prebid timeout. If you ask me how much it is higher, that depends on your site's technical details. 

To ensure that the set Failsafe timeout value will never equal or lower the Prebid timeout, use Prebid timeout as the variable in the formula.

For example,  set Failsafe_timeout=Prebid_timeout + 300.

The best practice to start your Failsafe timeout settings is below 3000 milliseconds.

Do consistent optimization

The auction dynamics are built around multiple parameters that change every minute. Therefore, you cannot follow the simple set–it and leave-it strategy for a timeout. Consistent optimization at frequent intervals is essential to tune Prebid timeout to adapt to changes.

The optimization will bring better ad yield if you use granular data like bid response time, page load time, user engagement metrics, bid rate, win rate, network performance, geo, devices data, and historical performance of each bidder and auction. 

Leverage Mile's Automation

Mile is an advanced AdTech platform designed to streamline Prebid optimization and maximize your revenue through automation. Our custom-built ad management solution streamlines Prebid optimization and maximizes your revenue through automation and AI-powered tools. 

Manual configuration of Prebid can be a complex and time-consuming process. Mile tackles this by automating several key aspects. Our automated bidder selection analyzes your setup and automatically selects the best-performing bidder partners, eliminating the need for manual research and testing.

Prebid timeouts define how long the ad exchange waits for bids before moving on. Mile can dynamically adjust these timeouts based on factors like user device, location, and content type. This ensures optimal performance for each impression by finding the sweet spot between maximizing bids and maintaining a good user experience (fast loading times).

And to ensure that you make the best revenue out of every session, we have advanced tools like dynamic flooring. It is an AI-powered technology that computes dynamic floor prices and inserts them into the auction. 

Using such automated tools to fetch dynamic data faster leaves you with a better range to optimize Prebid timeout. Eventually, you can combat the tradeoff between user experience and increased timeout rate to increase your ad revenue to new heights. 

It’s Time to Timeout

Setting optimal Prebid timeout is a game of intricate complexities. There, you need to balance user experience and missing revenue opportunities at the same time.

Once you find a way to reach reliable Prebid timeout by considering all differences and granularity, You can elevate your Prebid revenue to new heights by not overwhelming users with higher page loading times.

But how will you get there? Innovation and technology are at your rescue to break the constraints and beat the odds. And Mile can be your best destination to get all this.

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