Send All Bids vs Top Price in Prebid: What Publishers Need to Know

Managing header bidding with Prebid means making technical choices that can shape your operational efficiency and ad revenue. One of the most fundamental decisions is whether to send every eligible bid to your ad server (the default) or just the highest bid. Each approach has significant implications for reporting, line item complexity, and troubleshooting flexibility.

If you’ve ever tangled with hundreds or thousands of line items in Google Ad Manager or struggled to answer a demand partner’s performance question, this decision hits close to home. Let’s break down what “Send All Bids” and “Send Top Price” actually mean for your setup, and how to choose the right strategy for your team.

Understanding ‘Send All Bids’ in Prebid

By default, Prebid will send all bids that arrive before the configured timeout to your ad server. This setting buffers your operational visibility and can fuel more detailed analytics, but it adds substantial complexity behind the scenes.

Why Send All Bids?

Sending every bid—even those that weren’t the highest—gives your ad server a complete view of demand partner activity. This is crucial if you need granular reports, want to audit partner fulfillment, or must meet contractual reporting obligations.

Operational Impact: Line Items and Key Values

When you send all bids, you’re forced to create line items for every price bucket, multiplied by each demand partner. For example, 200 price points and 10 bidders leads to 2,000 line items. Each line item also requires unique key-value pairs that include bidder-specific info, pushing your system toward the technical limits of platforms like Google Ad Manager (e.g., 20-character key name limits).

Data Volume and Troubleshooting

Sending all bids dramatically increases the amount of data your ad server must process. With many bidders and key values, query strings can quickly exceed several thousand characters, raising the risk of data truncation or latency. While this provides rich troubleshooting data, it can create new operational headaches if not properly managed.

The ‘Send Top Price’ Approach: Simplicity at a Cost

Opting to send only the highest bid from Prebid to your ad server is a minimalist alternative. This approach drastically cuts down setup effort and ongoing maintenance, but sacrifices granular reporting.

Setup and Data Flow

With only the top bid forwarded per ad call, the number of required line items and key values drops dramatically. For instance, with 200 price points, you only need 200 line items, regardless of bidder count. The same handful of generic key values are used for all bidders, keeping your ad server configuration simple and manageable.

Reporting Limitations

You’ll only see data for the winning bid within your ad server. If you need to answer which partners bid on your inventory or diagnose partner-specific issues, you’ll have to rely on Prebid-side logs—or go without that visibility. This makes advanced troubleshooting or auditing harder, but if simplicity and speed are your top priorities, this trade-off might be worth it.

How This Choice Affects Google Ad Manager (GAM) and Header Bidding Flow

Your selection between ‘Send All Bids’ and ‘Send Top Price’ ripples out across your GAM setup, impacting line item management, targeting precision, and the data available for optimization workflows.

Real-World Example: Scaling Pain Points

Suppose you scale from 3 to 10 demand partners. With ‘Send All Bids,’ your line item and key-value needs more than triple—each new partner multiplies the workload. Without strict controls, setup and ongoing maintenance can grow unmanageable, especially for lean teams.

Choosing for Control or Simplicity

If operational agility and robust troubleshooting are non-negotiable, ‘Send All Bids’ is essential—just be prepared for significant setup overhead. For publishers who favor lean ops and can live without full cross-partner transparency, ‘Send Top Price’ may be the better path.

What this means for publishers

This decision shapes everything from your team’s workload to the accuracy of your revenue reports. Sending all bids gives you unmatched process visibility and helps satisfy partner transparency requirements, but comes with the cost of complicated ad server configurations and potential data overload. Opting to send only the top price bid slashes operational overhead and reduces the risk of server-side issues, but means you’ll lose insight into how every demand partner performs on individual impressions. Balancing these trade-offs is critical for both scaling your tech stack and optimizing for revenue.

Practical takeaway

Publishers need to align their Prebid bid forwarding strategy with their internal resources and business priorities. If you require detailed, partner-level reporting or expect to audit demand partner behavior regularly, invest the time to implement and manage a ‘Send All Bids’ setup—automate where possible and closely monitor data limits.

If your operation prioritizes ease-of-use and can accept coarser ad server reports, ‘Send Top Price’ can keep things simple and scalable, especially for smaller teams or those just getting started with header bidding. Whichever approach you choose, document your configuration carefully, keep an eye on ad server data constraints, and revisit your decision as your programmatic strategy evolves.