What is timeout rate?
Timeout rate is the share of bid requests for which a bidder's response did not reach the exchange before the auction deadline in BidRequest.tmax. A timed-out response is discarded whatever it contains, so the bidder loses the auction without the exchange counting a bid. Rising timeouts point at network distance, slow decisioning, or a deadline set too tight, not at pricing.
Also called: bidder timeout rate, timeouts, late bids.
How it works
BidRequest.tmax is in milliseconds and includes network time in both directions. If the exchange allows 120 ms and the round trip between exchange and bidder takes 50 ms, the bidder has about 70 ms to decide. Bidders measure their timeout rate by comparing their own response times with that remaining budget, and exchanges report it per bidder because it affects how much traffic they keep sending.
A timeout and a no-bid look the same on a win-rate report but have different fixes. A no-bid is a decision; a timeout is a latency failure. A bidder that cannot finish in time should answer quickly with a no-bid, optionally with BidResponse.nbr code 15 (Insufficient Auction Time), rather than send a late bid that will be thrown away.
Common causes are bidder endpoints in a different region from the exchange, connections that are not kept alive, uncompressed payloads, and tail latency that a healthy average hides. On the exchange side, a missing or implausible BidRequest.tmax, such as a value that looks like seconds rather than milliseconds, leaves bidders guessing at the budget.
Read more
Related terms
Every term is in the glossary.