What Each Term Actually Means
A 301 redirect is a server-side HTTP instruction that tells browsers and crawlers: the resource at URL A has permanently moved to URL B. The '301' is the status code in the HTTP response header. It is a technical mechanism — a routing rule — not a ranking signal in itself.
Link equity (sometimes called 'link juice') is the ranking authority that a hyperlink passes from one URL to another. It accumulates on a URL based on the quality and quantity of backlinks pointing to it, and it flows outward through links on that page. Link equity is a measure of value, not a mechanical action.
The confusion between the two arises because a 301 redirect transfers link equity from the old URL to the new one. But the redirect is the pipe; the equity is what flows through it. One is infrastructure, the other is the asset moving through that infrastructure.
How Each One Works Mechanically
When a server returns a 301 status code, search engine crawlers record the redirect chain and eventually consolidate their index entry: the old URL is dropped, the new URL inherits the old URL's signals. This happens at the crawler level — Googlebot follows the redirect, updates its graph, and re-evaluates the destination page.
Link equity flows differently. It originates with external sites that link to your URL. Each linking page passes a fraction of its own authority through the anchor tag to your page. That equity accumulates on your URL and then redistributes outward to every page your URL links to internally. The amount passed per outbound link decreases as the number of outbound links grows.
The mechanical interaction: once a 301 is in place, any crawl of the old URL ends at the new URL. Backlinks pointing to the old URL still exist on third-party sites — those sites do not change. The redirect instructs search engines to attribute the equity those backlinks generate to the new destination URL instead.
Where They Overlap — and Where They Diverge
The overlap is narrow but critical: a 301 redirect is the primary tool for relocating link equity from one URL to another. If a product page URL changes — due to a site migration, a URL restructure, or a product rename — a 301 redirect is what prevents the backlink equity built on the old URL from becoming stranded.
They diverge everywhere else. A 301 redirect with no backlinks pointing to the old URL transfers nothing of ranking value — the redirect functions correctly as a user-experience tool, but there is no equity to move. Conversely, link equity exists and accumulates independently of any redirect. A URL with 500 strong backlinks and no redirect issues simply holds that equity on its own.
Another divergence: redirects can be undone or changed; link equity cannot be manufactured by the store owner directly. You implement a redirect unilaterally in your server config or CMS. Earning link equity requires third-party sites to link to you — it is external by definition.
Common Ecommerce Scenarios Where Both Apply
During a platform migration — say, moving from one ecommerce platform to another with new URL structures — every old URL that carried backlinks needs a 301 redirect to the corresponding new URL. Without it, the link equity those product and category pages earned stays attached to dead URLs that return 404 errors.
When a product is discontinued and replaced by a successor, a 301 from the old product URL to the replacement passes the accumulated equity forward. If the old page had editorial coverage or affiliate links pointing to it, those continue contributing to the new URL's authority.
URL consolidation — collapsing duplicate product pages created by parameter variations (e.g., ?color=red, ?color=blue) into one canonical URL via 301 redirects — concentrates split equity onto a single URL, which typically improves that page's ranking position for its target keywords.
What Ecommerce Operators Should Prioritize
Audit backlink profiles before any URL change. Use a crawl tool to identify which existing URLs have external backlinks pointing to them. Those URLs are the ones where a missing 301 redirect causes real equity loss — not every URL change is equally costly.
After implementing 301 redirects, verify that the destination URLs are indexable, not blocked by robots.txt, and not themselves redirecting further. A redirect chain — old URL → intermediate URL → final URL — introduces unnecessary equity dilution. Every hop in a chain reduces the signal passed to the final destination.
Treat 301 redirects as permanent maintenance, not a one-time fix. When products return, when URLs change again, or when site architecture evolves, the redirect map needs updating. An outdated redirect map accumulates chains and loops that erode the equity the original redirects were set up to preserve.