GitHub 304 Responses Still Drain Rate Limit Without an Authorization Header

A developer testing the GitHub REST API discovered that unauthenticated conditional requests returning 304 Not Modified responses still decrement the rate limit counter, consuming quota despite transferring zero bytes. GitHub's documentation does state that the rate-limit exemption for 304 responses applies only when requests are made with a valid Authorization header, but this condition appears explicitly in just two of five relevant mentions on the page. The ambiguity led the developer to initially believe ETags could be used to poll GitHub endpoints without spending quota, a misconception they had also passed on to others. Testing on July 29, 2026 confirmed that three consecutive conditional requests each reduced the unauthenticated bucket of 60 requests per hour by one. The developer notes that whether the exemption works correctly for authenticated requests remains unverified, as that scenario was not tested.