# Data Compression (gzip)¶

BidSwitch supports JSON and Compressed JSON (gzip) as data formats for bid requests and bid responses. It is recommended to use Compressed JSON to minimize the amount of data exchanged between BidSwitch and the Buyer, as this reduces latency times between servers.

## Sending Bid Responses to BidSwitch¶

Sending bid responses in Compressed JSON does not require special configuration. The bidder is only required to send a Content-Encoding: gzip header in the responses where the compression is used.

## Receiving Bid Requests from BidSwitch¶

Once enabled, BidSwitch starts sending bid requests in Compressed JSON. All such bid requests carry an extra HTTP header Content-Encoding: gzip. It is recommended for the bidder to check for this HTTP header to distinguish between JSON and Compressed JSON bid request formats, as even when compression is enabled some Bid Requests may arrive uncompressed. In this case the Content-Encoding: gzip header is absent.