Cloudflare Fundamentals - Improved HTTP/3 client cancellation reporting

<p>Cloudflare has improved how it handles and reports client-cancelled HTTP/3 requests across Free, Pro, Business, and Enterprise plans. Customers now get a clearer view of client behavior in Cloudflare analytics and, where available, logs.</p> <p>Previously, Cloudflare did not always stop an HTTP/3 request when the client cancelled its request stream. Some cancellations were already recorded as <code>499</code>, while others continued to the origin and showed the eventual upstream status.</p> <p>Cloudflare now stops affected requests sooner, reducing unnecessary origin work, and records them as <code>499</code>. Customers may notice more <code>499</code> status codes for HTTP/3 traffic. This reflects more consistent reporting of existing cancellations, not an increase in failed requests.</p> <p>Customers who use <code>499</code> status codes in availability calculations should consider excluding them from server-side error rates because they represent requests cancelled by clients.</p> <p>For more information, refer to <a href="https://developers.cloudflare.com/support/troubleshooting/http-status-codes/4xx-client-error/error-499/">Error 499</a>.</p>