How to Filter IVT and Bot Traffic from Prebid Auctions
Invalid traffic (IVT) is any ad request that does not come from a real person: crawlers, headless browsers, automation scripts, scraping tools and other non-human visitors. When these requests reach your Prebid auctions they waste bidder budgets, drag down your CPMs and can put your inventory on buyer blocklists.
The IVT filter lets you keep this traffic out of your Prebid auctions. Flagged sessions receive no bid requests, so your demand partners only see genuine visitors.
Typical use cases:
- Protecting bidder relationships and CPMs by keeping bot traffic out of the bidstream.
- Reducing wasted bid requests and the page overhead that comes with them.
- Meeting buyer and SSP expectations on traffic quality without adding another vendor tag.
How It Works
The filter is powered by Transfon Security. Each visit is scored in real time using a combination of signals observed in the browser and Transfon's traffic intelligence network. The check runs alongside the normal page load and does not add a visible delay for genuine visitors.
- Clean visitor: the auction runs as usual with your full bidder line-up.
- Flagged visitor: BiddingStack skips the Prebid auction for that session. Your ad server continues to serve as normal, so the page still renders and direct campaigns are unaffected.
- Scoring unavailable: if the check cannot complete in time, the visitor is treated as genuine and the auction runs. The filter never blocks real users because of a network issue.
No changes to your placements, bidders or ad server setup are required.
1. Open the Project
From the sidebar, navigate to Projects and open the project you want to protect.
2. Enable the IVT Filter
In the Demand section, switch on Enable IVT filter for Prebid.
| Field | Purpose | Options / Configuration |
|---|---|---|
| Enable IVT filter for Prebid | Skips the Prebid auction for sessions identified as invalid or bot traffic. | Default: off. Turn on per project. Applies to all placements in the project. |
3. Save and Publish
Click Save Changes and publish the project configuration. The filter takes effect once the updated configuration is live on your site.
What to Expect
- Bid request volume may drop slightly. This is the invalid traffic that is no longer reaching your bidders.
- Fill rate and CPMs on the remaining requests typically improve, since bidders are pricing genuine impressions.
- Ad server reports still show the full page view count. The filter changes what enters the Prebid auction, not what your ad server sees.
Combined with blocking control and the per-bidder geo whitelist, the IVT filter gives you a cleaner bidstream: the right bidders, in the right markets, for real visitors only.