# Content-Encoding header > Indicates the compression encoding that has been applied to the message body. Source: https://apiguide.dev/headers/content-encoding Direction: both Registered: yes Defined in: RFC 9110, Section 8.4 Updated: 2026-07-10 ## What is the Content-Encoding header? The `Content-Encoding` header lists any compression that has been applied to the representation body, so the recipient knows which transformation to reverse before decoding. Common values are `gzip`, `br` (Brotli), `zstd`, and `deflate`. ## API Usage & Best Practices * **Pair with `Accept-Encoding`**: A server should only apply an encoding that the client advertised as acceptable in its `Accept-Encoding` request header. * **Reduce payload size**: Compressing JSON responses with `gzip` or `br` can dramatically cut bandwidth for API responses. * **Order matters**: When multiple encodings are applied, list them in the order they were applied so the client can reverse them correctly. ## Examples ```http HTTP/1.1 200 OK Content-Type: application/json Content-Encoding: gzip ```