Unattributed Navigation Overhead (UNO) Is Underrated

· Harry Roberts · Aug. 19, 2026, 2:23 p.m.
web-performance Navigation Timing Cross-Origin Redirects Time to First Byte
Summary
This blog post discusses Unattributed Navigation Overhead (UNO), focusing on aspects of Time to First Byte (TTFB) that Navigation Timing does not cover, particularly concerning hidden cross-origin redirects.
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