How to use download compression in cURL

Download compression uses gzip or deflate to reduce data size and accelerate transfers. Many servers return compressed content if the client indicates support via the Accept-Encoding header.

With cURL, specifying Accept-Encoding or using --compressed requests compressed data and decompresses it upon arrival. This improves efficiency, especially when handling large HTTP responses.

Integrating compression into cURL workflows conserves bandwidth and enhances performance. Applying --compressed automates negotiations, simplifying efficient data retrieval.

1. Open a terminal.
2. Request compressed data using Accept-Encoding.

   $ curl --header "Accept-Encoding: gzip, deflate" "https://www.example.com/data"

   The server returns compressed data, automatically decompressed by cURL.

3. Save the decompressed output to a file.

   $ curl --header "Accept-Encoding: gzip, deflate" "https://www.example.com/data" --output data.json

   The output file is stored uncompressed.

4. Optionally save compressed data and decompress manually.

   $ curl --header "Accept-Encoding: gzip" "https://www.example.com/data" --output data.gz
   $ gunzip data.gz

   Manual decompression offers flexibility.

5. Use --compressed for automatic compression handling.

   $ curl --compressed "https://www.example.com/data"

   --compressed simplifies adding necessary headers and decoding responses.