Link juice is an informal SEO term describing the ranking power, or SEO equity: that passes from one webpage to another through hyperlinks. When a webpage links to another page it passes some of its authority, trust, and ranking potential to the destination, the linked page receives a portion of the linking page’s accumulated ranking signals. This transfer of ranking power through links is what the term link juice captures, authority flowing like liquid from one page to another through the connections between them.

The concept of link juice originates from Google’s PageRank algorithm, the foundational ranking mechanism that Google’s founders Larry Page and Sergey Brin described in their 1998 paper. PageRank modelled the web as a network of pages connected by links and calculated each page’s importance based on the number and quality of links pointing to it, weighted by the importance of the linking pages. A link from an important page passed more ranking power than a link from an unimportant page. Links from pages with many outgoing links passed less power per link than links from pages with few outgoing links. PageRank provided the mathematical foundation for what practitioners now colloquially call link juice.

While Google has evolved far beyond the original PageRank formula, incorporating hundreds of additional ranking signals, machine learning, and user behaviour data, links remain one of the most important ranking factors. The fundamental principle of link juice, that links pass ranking authority and that the quality and quantity of inbound links significantly affects a page’s ability to rank, remains valid and central to SEO practice.

How link juice works

Link juice flows through the web’s link graph, the network of hyperlinks connecting pages to each other. Understanding how this flow works clarifies why link building, redirect management, and internal linking structure all significantly affect SEO performance.

Inbound links pass authority: when an external page links to example.com/page that link passes a portion of the linking page’s authority to example.com/page. The amount of authority passed depends on several factors, the authority of the linking page, the number of other outgoing links on the linking page, whether the link is followed or nofollowed, and the relevance of the linking page’s topic to the linked page’s topic.

A link from a high-authority site, a major newspaper, a university, a well-known industry publication, passes significantly more link juice than a link from a low-authority blog with minimal traffic and few inbound links of its own. This weighting means that the quality of inbound links matters as much as, or more than, the quantity.

PageRank distribution model: the original PageRank model distributes a page’s authority equally among all its outgoing links. A page with authority score 100 and 10 outgoing links passes approximately 10 units of authority through each link, minus a damping factor that models the probability of a random web surfer stopping rather than continuing to click. A page with the same authority and 100 outgoing links passes approximately 1 unit through each link.

This dilution effect means that links from pages with fewer outgoing links pass more juice per link than links from pages with many outgoing links. A dedicated resource page on a high-authority site that links to only 5 external resources passes significantly more juice per link than a high-authority page with 200 outgoing links.

Link juice accumulation: pages accumulate link juice over time as more inbound links are acquired. A page with many high-quality inbound links has accumulated significant authority, which it then distributes to pages it links to. The web’s link graph creates a complex network of authority flows where authority from high-quality external links percolates through internal link structures to reach deep pages in a site’s hierarchy.

Internal link juice flow: link juice is not limited to external links. Internal links, links from one page on a site to another page on the same site, also pass link juice. A site’s homepage typically has the most accumulated authority, the most inbound links. Internal links from the homepage to key section pages pass homepage authority to those sections. The internal linking structure determines how authority flows through a site, pages that are well-linked internally accumulate more authority than pages buried deep in the site with few internal links pointing to them.

Link juice and redirects

The relationship between link juice and redirects is one of the most practically important aspects of redirect management, understanding it correctly determines how much SEO value is preserved or lost when URLs change.

301 permanent redirects pass link juice: when a URL changes and a 301 permanent redirect is configured from the old URL to the new URL the link juice from backlinks pointing to the old URL is passed through the redirect to the new URL. External sites that linked to old-url.com/page continue to pass their link juice, the redirect transfers it to new-url.com/page. This equity transfer is the primary mechanism through which SEO value is preserved during domain migrations, URL restructuring, and site consolidations.

The equity transfer through 301 redirects is not perfectly lossless, some link juice is lost at each redirect hop. Google has stated that the transfer through 301s is largely complete but the exact percentage retained versus lost is not publicly disclosed and has changed over time. The general principle is that a direct link passes more juice than a redirected link, but a redirect preserves substantially more juice than no link at all.

302 temporary redirects do not reliably pass link juice: temporary redirects signal to search engines that the original URL will return, the redirect is a temporary state. Search engines keep the original URL indexed and do not transfer accumulated authority to the redirect destination. Link juice from backlinks to the original URL continues to be attributed to the original URL, not the destination. Using 302 redirects for permanent URL changes is a common SEO mistake that causes equity loss because the transfer never happens.

Redirect chains dilute link juice: each redirect hop in a chain loses some link juice, the cumulative loss across a chain of multiple redirects can be significant. A three-hop redirect chain from URL A to URL B to URL C passes less juice from URL A’s backlinks to URL C than a direct redirect from URL A to URL C would. Minimising redirect chain length, collapsing multi-hop chains to direct single-hop redirects, preserves maximum link juice.

Broken redirects lose all link juice: a redirect that returns an error, 404 Not Found, 500 Server Error, or any other error response, passes no link juice. Backlinks pointing to a broken redirect are wasted in terms of their SEO contribution. Monitoring redirect functionality and fixing broken redirects promptly preserves the link juice from backlinks pointing to redirect source URLs.

HTTP to HTTPS redirects pass link juice: when a site migrates from HTTP to HTTPS and configures 301 redirects from all HTTP URLs to their HTTPS equivalents the link juice from HTTP backlinks transfers to the HTTPS URLs. Backlinks pointing to http://example.com/page pass their juice through the HTTP-to-HTTPS redirect to https://example.com/page. HTTPS migration with correctly configured redirects preserves all accumulated link juice, the migration itself does not cause link juice loss.

Factors affecting link juice value

Not all links pass equal link juice, several factors determine how much authority a specific link passes.

Linking page authority: the most important factor. Links from pages with high accumulated authority pass more juice than links from low-authority pages. Domain authority, a metric calculated by SEO tools like Moz, Ahrefs, and Semrush based on backlink profile quality, provides a proxy for how much juice a domain’s pages are likely to pass. High-domain-authority sites are the most valuable link sources.

Number of outgoing links on the linking page: as described in the PageRank model a page’s authority is divided among its outgoing links. A page with 5 outgoing links passes roughly 5 times more juice per link than a page with 25 outgoing links, assuming equal authority. Links from pages with few outgoing links are more valuable per link.

Link placement and context: editorial links, links placed naturally within content because the linking author found the destination genuinely useful, are more valuable than footer links, sidebar links, or links in boilerplate that appears on many pages. Search engines evaluate link context and placement as signals of editorial intent.

Anchor text: the visible text of a hyperlink, the anchor text, provides context about what the linked page is about. Anchor text with relevant keywords signals topical relevance between the linking and linked pages, contributing to the linked page’s authority for those topics. Over-optimised anchor text, many links using the same exact keyword phrase, is a spam signal that may diminish link value.

Topical relevance: links from pages topically relevant to the linked page pass more juice relevant to the shared topic than links from unrelated pages. A link to a redirect management tool from an SEO blog passes more topically relevant authority than a link from a cooking website.

Follow vs nofollow: the rel="nofollow" attribute on a link instructs search engines not to follow the link for ranking purposes, nofollow links traditionally did not pass link juice. Google introduced additional link attributes, rel="sponsored" for paid links and rel="ugc" for user-generated content, alongside nuanced guidance that these attributes are hints rather than directives. The treatment of nofollow links has evolved, Google may pass some juice through nofollow links as part of its overall link evaluation. Followed links are generally assumed to pass full juice while nofollowed links pass reduced or no juice.

Link juice in domain management

Link juice considerations directly shape decisions about domain parking, domain migration, domain consolidation, and redirect portfolio management.

Maintaining redirect sources for link juice: the primary reason to maintain registrations and redirect configurations for old domains long after they have been replaced is link juice preservation. As long as backlinks pointing to old domains exist those links continue passing juice to the redirect destination through correctly configured 301 redirects. Allowing an old domain to expire, breaking the redirect, wastes all the link juice from its backlink profile.

The standard recommendation is to maintain old domain redirects for at least two to three years after migration, longer for domains with significant backlink profiles. Some organisations maintain redirects indefinitely for high-value domains where the backlink profile is extensive and the link juice value justifies the ongoing registration and redirect management cost.

Expired domain acquisition for link juice: acquiring expired domains specifically to capture their accumulated backlink juice is a legitimate SEO strategy. A domain with a strong backlink profile, many high-quality inbound links, passes that backlink juice to the acquirer’s primary domain through a 301 redirect after acquisition. The acquired domain serves only as a redirect source, its value is entirely in the link juice its backlinks deliver to the redirect destination.

Due diligence for expired domain acquisition must include backlink quality analysis, verifying that the backlinks are from genuine high-quality sites rather than from link farms or spam networks that could harm rather than help the redirect destination.

Domain consolidation and link juice concentration: consolidating multiple domains onto one primary domain concentrates all their accumulated link juice at the primary, the combined backlink profiles of all consolidated domains contribute their equity to the primary through permanent redirects. A consolidation from three moderate-authority domains onto one primary produces a primary with authority approaching the combined total of all three, stronger than any individual pre-consolidation domain.

Link juice from domain parking: parked domains configured with 301 redirects to the primary domain pass any link juice from their backlinks. Brand protection domains may have accumulated backlinks, perhaps because competitors linked to them, because old marketing materials referenced them, or because they were previously active sites. Even minimal backlink profiles contribute link juice to the primary domain through correctly configured redirects.

Measuring link juice

Link juice itself is not directly measurable, Google does not expose PageRank scores externally. SEO tools calculate proxy metrics that estimate the link equity flowing through a site’s backlink profile.

Domain Authority, Moz: a 1-100 scale metric estimating the overall ranking strength of a domain based on its backlink profile. Higher DA correlates with stronger link juice flow from that domain’s pages. Calculated by Moz using their link index.

Domain Rating, Ahrefs: Ahrefs’ equivalent to Moz’s Domain Authority. A 1-100 scale metric based on the quantity and quality of backlinks in Ahrefs’ index. Useful for comparing the relative link equity of domains.

URL Rating, Ahrefs: page-level equivalent of Domain Rating. Estimates the link equity of a specific URL based on its backlink profile. More granular than domain-level metrics for evaluating specific pages.

Page Authority, Moz: Moz’s page-level authority metric. Estimates the ranking strength of specific pages based on their inbound link profiles.

These metrics are useful proxies for link juice but are imperfect approximations of Google’s actual link evaluation. Different tools use different link indexes and different calculation methodologies, scores vary between tools for the same domain or page. The metrics are most valuable for relative comparison, comparing link equity between domains or pages, rather than as absolute values.