Send and receive compressed traffic using gzip

DSPs
Last Updated: February 12, 2026•

You can receive bid requests and send bid responses that are compressed using gzip. By using bid compression, DSPs can see a 20-30% reduction in bandwidth utilization which may contribute to lower latency, infrastructure costs, and fewer timeouts. To enable bid compression with Index, contact your Index Representative. To start sending and receiving compressed traffic using gzip:

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By default, Index adds an Accept-Encoding: gzip HTTP header to the bid request to specify that we accept compressed bid responses from DSPs.

Note: To opt-out of receiving the Accept-Encoding: gzip field for bid requests, contact your Index Representative.

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If you have enabled bid compression, Index adds a Content-Encoding: gzip HTTP header to the bid request to specify that it is a compressed request.

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You can send a compressed gzip bid response to Index by including the following required fields in the HTTP header:

  • Content-Encoding: gzip : Specifies that you have sent a compressed bid response.
  • Content-Length header: Specifies the response size. For more information on the Content-Length field, see the HTTP header fields in the List of supported OpenRTB bid response fields for DSPs.