CompressionStream: CompressionStream() constructor

Baseline Widely available *

This feature is well established and works across many devices and browser versions. Its been available across browsers since May 2023.

* Some parts of this feature may have varying levels of support.

Note: This feature is available in Web Workers.

The CompressionStream() constructor creates a new CompressionStream object which compresses a stream of data.

Syntax

new CompressionStream(format)

One of the following allowed compression formats:

"brotli": Compresses the stream using the Brotli algorithm.
"gzip": Compresses the stream using the GZIP format.
"deflate": Compresses the stream using the DEFLATE algorithm in ZLIB Compressed Data Format. The ZLIB format includes a header with information about the compression method and the uncompressed size of the data, and a trailing checksum for verifying the integrity of the data
"deflate-raw": Compresses the stream using the DEFLATE algorithm without a header and trailing checksum.
"zstd": Compresses the stream using the ZSTD algorithm.

TypeError: Thrown if the format passed to the constructor is not supported.

In this example a stream is compressed using gzip compression.

const compressedReadableStream = inputReadableStream.pipeThrough(
  new CompressionStream("gzip"),
);

Specification
Compression # dom-compressionstream-compressionstream

Was this page helpful to you?

Yes No

This page was last modified on Jun 22, 2026 by MDN contributors.