coderef

Compression streamsBaseline · Widely available

The CompressionStream and DecompressionStream APIs compress and decompress data using the gzip or deflate formats.

Supported in all major browsers for at least 30 months — safe to use without fallbacks. Baseline since May 9, 2023. Widely available since Nov 9, 2025.

How to use ↓Compare browsers

Browser support

DesktopChrome
1–79Not supported
80+Supportedsince Feb 4, 2020
Current: 155
Edge
12–79Not supported
80+Supportedsince Feb 7, 2020
Current: 154
Firefox
1–112Not supported
113+Supportedsince May 9, 2023
Current: 157
Safari
1–16.3Not supported
16.4+Supportedsince Mar 27, 2023
Current: 27
MobileChrome Android
18–79Not supported
80+Supportedsince Feb 4, 2020
Current: 155
Firefox Android
4–112Not supported
113+Supportedsince May 9, 2023
Current: 157
Safari iOS
1–16.3Not supported
16.4+Supportedsince Mar 27, 2023
Current: 27

How to use

This feature is Baseline widely available — use it freely, no fallback needed.

Example

Full syntax and examples are on MDN: CompressionStream.

Feature detection

JS · check before using
if ("CompressionStream" in globalThis) {
  // CompressionStream is available
} else {
  // load a polyfill or use a fallback
}

Documentation (MDN)

Specification

Sub-features

Support for each part of the feature (16). The overall table above shows when the whole feature works.

Sub-featureChromeEdgeFirefoxSafariChrome AndroidFirefox AndroidSafari iOS
CompressionStream808011316.48011316.4
CompressionStream.CompressionStream808011316.48011316.4
CompressionStream.CompressionStream.brotli✕✕14718.4✕14718.4
CompressionStream.CompressionStream.deflate808011316.48011316.4
CompressionStream.CompressionStream.deflate-raw10310311316.410311316.4
CompressionStream.CompressionStream.gzip808011316.48011316.4
CompressionStream.readable808011316.48011316.4
CompressionStream.writable808011316.48011316.4
DecompressionStream808011316.48011316.4
DecompressionStream.DecompressionStream808011316.48011316.4
DecompressionStream.DecompressionStream.brotli✕✕14718.4✕14718.4
DecompressionStream.DecompressionStream.deflate808011316.48011316.4
DecompressionStream.DecompressionStream.deflate-raw10310311316.410311316.4
DecompressionStream.DecompressionStream.gzip808011316.48011316.4
DecompressionStream.readable808011316.48011316.4
DecompressionStream.writable808011316.48011316.4