WebTransport connection statistics

Category: Network / Connectivity
Type: Chromium catches up
Status: Proposed (Chrome Proposed)
Intent stage: None

Breaking change: No
Enterprise impact: None
Chromium flag: enable-experimental-web-platform-features
Spec maturity: Published standard
Web Platform Tests: Yes

WPT details: https://wpt.fyi/results/webtransport/stats.https.any.html

Summary

WebTransport.getStats() provides asynchronous statistics for an existing connection: round-trip time measurements when available, an estimated sending rate when available, and counts of expired, lost, and dropped datagrams. Statistics remain accessible after the connection closes. Chromium does not currently expose connection byte or packet totals.

Motivation

WebTransport applications need to distinguish connection latency, congestion, and datagram loss or expiration from application-side delays. A single asynchronous call exposes a snapshot of the existing connection's health to help developers adapt sending behavior and troubleshoot problems. It does not create a connection or change how application data is transmitted.

Standards & signals

Specification: https://w3c.github.io/webtransport/#dictdef-webtransportconnectionstats
Firefox: Shipped/Shipping — WebTransport.getStats() shipped in Firefox 158, released October 13, 2026.
Safari: Shipped/Shipping — Safari 27.2 exposes WebTransport.getStats(), but its WebKit(7625.2.8) implementation returns default-initialized connection statistics. WebKit main has since added bytesSent and bytesReceived counters.
Web developers: Positive — The Interop 2026 WebTransport proposal received 28 positive reactions. Developers also reported active WebTransport use and significant cross-engine differences.
Tracking bug: https://issues.chromium.org/issues/573538454

Ecosystem

Web Platform Tests: https://wpt.fyi/results/?q=webtransport%2Fstats
Chrome Platform Showcase: https://chrome-platform-showcase.paulkinlan-ea.deno.net/features
GenDN reference: https://gendn.paulkinlan-ea.deno.net/features
chrome.dev demos search: https://www.google.com/search?q=site%3Achrome.dev+WebTransport%20connection%20statistics
MDN Web Docs: https://developer.mozilla.org/en-US/search?q=WebTransport%20connection%20statistics
Baseline status: https://webstatus.dev/?q=WebTransport%20connection%20statistics

Docs: https://developer.mozilla.org/en-US/docs/Web/API/WebTransport/getStats https://w3c.github.io/webtransport/#web-transport-connection-stats

Samples: https://github.com/MicrosoftEdge/Demos/tree/main/webtransport-getstats https://microsoftedge.github.io/Demos/webtransport-getstats

Explainers: https://github.com/w3c/webtransport/blob/main/explainer.md#stats

View on chromestatus.com