HTTP 499: Client Closed Request
HTTP 499 Client Closed Request is a non-standard status code logged by Nginx when the client closes the connection before the server finishes sending the response. This appears in Nginx access logs but is never sent to the client.
Status
499 Client Closed RequestExample
GET /news HTTP/1.1
Host: www.example.com
User-Agent: Mozilla/5.0
Accept: text/html
(user navigated away before the page finished loading)(no response sent — client closed the connection)
Nginx access log:
10.0.1.42 - - [28/Feb/2026:09:15:33 +0000] "GET /news HTTP/1.1" 499 0 "-" "Mozilla/5.0"How to Troubleshoot
Check server response times
If clients are timing out, the server may be too slow. Check application performance and response times.
Increase client timeout
If the server legitimately needs more time, increase the client's timeout setting.
Optimize slow endpoints
Identify and optimize the slow endpoints causing timeouts.
# Check Nginx access log for 499 responses:
# awk '$9 == 499' /var/log/nginx/access.log | awk '{print $7}' | sort | uniq -c | sort -rn | headCommon Causes
Client timeout
highThe client (browser, API client) timed out waiting for the server response and closed the connection.
User navigated away
highThe user clicked a link or closed the tab before the page finished loading.
Load balancer health check timeout
mediumA load balancer's health check request timed out and it closed the connection.
Related Status Codes
Frequently Asked Questions
This reference was compiled from official RFCs, protocol specifications, and hands-on troubleshooting experience. AI tools were used primarily for formatting and organizing the content on the page.