Measuring how much header bidding slows your page

Measuring how much header bidding slows your page

Every auction adds a little delay. You want to know exactly how much.

The test:
— 1. Note your page's load time with the auction code switched on.
— 2. Comment out the wrapper and load the page again — that's your baseline.
— 3. Subtract: the difference is your real header bidding cost in milliseconds.
— 4. If it's over 500ms, your timeout is likely too generous.
— 5. Trim the timeout by 200ms and re-measure before touching anything else.

Do this on a phone over a normal connection, not just fast office WiFi.

In plain English: load the page with and without the auction, and the gap is what header bidding costs you.