Several things can break, and on a high-traffic page each one costs more, because the value flowing through that page is exactly what is at stake. The reassuring line that “301s are safe, just redirect it” is true only when the redirect is built correctly, and the failure modes are specific enough to plan around. Redirecting a page that earns real traffic is not a routine swap; it is moving a load-bearing asset, and the risks are worth naming before you touch it.
The first risk is a wrong or irrelevant target. If you point the redirect at a page that is not a true equivalent, search engines can treat it as a soft 404 and decline to pass the original page’s signals, so instead of inheriting the value you lose it. The second risk is the settling period: even a clean redirect to a strong target typically dips traffic temporarily while the change is re-evaluated and the new URL takes over the rankings, and on a high-traffic page that temporary dip is a meaningful loss while it lasts.
The third risk is breakage you do not control from the SEO side. Internal links pointing at the old URL, external bookmarks, and saved or shared links can all break or get bounced through extra hops, degrading the experience for the very visitors who relied on that page. The fourth risk is chains and loops: a redirect that points to another redirect, or circles back on itself, compounds the delay, leaks more signal at each hop, and can fail outright, turning one careful change into a tangle.
So when the page in question carries real traffic, redirect it deliberately. Send it to a genuine equivalent that fully covers the original intent, not a loosely related page. Test the destination to confirm it resolves in a single hop with no chain or loop, update internal links to point straight at the new URL, and monitor traffic and rankings through the settling period so you catch a soft-404 or a stalled transfer early. Treat the redirect as a move that puts known value at risk, and protect that value at every step.