Ask a room of business owners whether they link to other websites from their own content and many will say no, on principle. The reasoning usually goes like this: links pass authority, so every link to someone else gives away some of yours, sends visitors off your site and might even help a competitor. Some go further and add nofollow to every external link "to be safe".
That instinct is understandable, but it is based on a misreading of how links work, and it often makes content worse. Pages that state facts without sources, recommend tools without naming them or summarise research without pointing to it are less useful to readers, and Google's own guidance encourages the opposite.
This guide explains what outbound links are, why the "leaking authority" fear is mostly a myth, what the evidence says about rankings, how linking out supports trust, how to choose destinations, when to use nofollow, sponsored and ugc, and how to audit outbound links before they turn into broken or risky ones.
What counts as an outbound link
An outbound (or external) link is a hyperlink on your site that points to a page on a different domain. It is the mirror image of a backlink: your outbound link is someone else's inbound link.
- Editorial outbound links are links you choose to include in content: citing a study, crediting a quote, recommending a tool or pointing to official documentation.
- Navigational and template links sit in headers, footers and sidebars: social profiles, parent companies, partner logos.
- Paid or sponsored links are placed because money, products or services changed hands: adverts, affiliate links, sponsored posts.
- User-generated links are added by visitors in comments, forums, reviews or profiles.
Each type has different rules. Editorial links are where most of the SEO and trust questions lie; paid and user-generated links are mainly a compliance question.
The myth of leaking link equity
The fear of "leaking" comes from a simplified picture of PageRank in which a page holds a fixed pot of authority and every outbound link drains some of it away. That is not how the model works.
In the PageRank model, a page's own value comes from the links pointing to it. Outbound links affect how much value the page passes on through each of its links, not how much it holds. Adding a link to a government statistics page does not reduce the authority of your page; it slightly changes how what your page passes is shared among all its links, internal and external. Google says PageRank has "evolved a lot" and remains part of its core ranking systems in its ranking systems guide, but it has never suggested that citing sources weakens a page. Our explainer on how link equity flows covers the model in more depth.
Google's link guidance is unusually direct on this point:
“Linking to other sites isn’t something to be scared of; in fact, using external links can help establish trustworthiness (for example, citing your sources).”
— Google Search Central, link best practices, Link best practices for Google
The same page adds: "Use nofollow only when you don't trust the source, and not for every external link on your site." Blanket nofollow on every outbound link is therefore not a protective measure. It simply tells Google you do not vouch for anything you cite.
What about sending visitors away?
A reader who clicks through to your source has usually got what they wanted from your page and wants to verify or go deeper. Readers who cannot verify a claim often leave anyway, and they are less likely to come back. If you are worried about losing visitors, place source links where they support a claim rather than at the very top of a page, and make your own next step (a related guide or a contact option) obvious.
Do outbound links help rankings? What the evidence says
This is where honest answers are messier. Google representatives have described outbound links mainly as a user-value issue rather than a ranking factor, while at least one well-known experiment suggested an effect.
| Evidence | What it says | Caveats |
|---|---|---|
| John Mueller, 2015 Webmaster Central hangout (via Search Engine Journal) | "We would say there's not any SEO advantage of linking to anyone else's site." | Statement about direct ranking benefit only |
| John Mueller, 2016 video (via Search Engine Journal) | External links "isn't specifically a ranking factor" | Same |
| John Mueller, 2019 Ask Google Webmasters video (via Search Engine Journal) | Linking out provides value to users | Frames the benefit as user value |
| Reboot Online experiment | Ten new sites targeting a made-up word; five linked to authoritative sources, five did not. The authors concluded relevant outgoing links had a positive impact | Small test on new domains with a nonsense keyword; page dates and link counts are inconsistent; does not prove the effect in competitive searches |
| Google's helpful content guidance | Asks whether content shows "clear sourcing, evidence of the expertise involved" | A content quality question, not a link-counting rule |
The fair summary is this: there is no good evidence that adding outbound links on its own will raise rankings, and Google says it does not reward linking out as such. There is good reason to believe that well-sourced, genuinely helpful pages do better over time, and citing sources is part of what makes a page well sourced. Search Engine Journal's review reaches a similar conclusion.
“Linking to other websites is a great way to provide value to your users.”
— John Mueller, Google, quoted by Search Engine Journal, Are Outbound Links a Google Ranking Factor?
How outbound links support trust and usefulness
Outbound links do practical jobs for a page, regardless of any direct ranking effect:
- They let readers verify claims. A statistic with a link to the original study is more credible than one without. Google's helpful content guidance asks whether content has "clear sourcing", and our guide to fact-checking content covers how to source properly.
- They show you know the field. Linking to the right standard, regulator or primary research signals expertise to readers and to anyone evaluating the page.
- They place your page in context. Links and the words around them help search engines understand what a page is about and which entities it relates to; see our guide to co-citation and co-occurrence.
- They make your page linkable. Journalists and bloggers prefer to cite pages that themselves cite sources, because it protects their own credibility.
- They build relationships. A genuine citation is a natural reason to contact the publisher you linked to, which is a gentler start to outreach than a cold request.
Choosing which sites to link to
Google's SEO Starter Guide advises you to "make sure you trust the resource you're linking to", to avoid search engines associating your site with the site you're linking to. Use these criteria when choosing a destination:
| Prefer | Avoid | Why |
|---|---|---|
| Primary sources: the original study, regulator, standard or official documentation | Articles summarising other articles | Primary sources stay accurate and are what experts expect |
| Pages with named authors, dates and their own sources | Anonymous pages with no date | You inherit some of the credibility of what you cite |
| Stable URLs on established sites | Pages likely to disappear (campaign pages, social posts) | Fewer broken links later |
| The most specific page that supports the claim | Homepages | Readers get straight to the evidence |
| Relevant competitors' research, when it is the best source | Refusing to cite anything a competitor published | Readers value the best answer; you gain credibility |
| Sites you would be comfortable being associated with | Spammy, hacked or low-quality sites | Google's guidance on trust and association |
A practical habit: when a writer adds a statistic, require the link to the page where the number was first published, and check the date. If the original cannot be found, rewrite the sentence without the number. Our content writing service works to that rule.
The same criteria work in reverse when you are looking for sites to earn links from. A site that cites carefully and links out thoughtfully is a better prospect than one whose outbound links are all commercial; our guide to link prospecting uses outbound link patterns as a qualification check.
When to use nofollow, sponsored or ugc
Google supports three link attribute values, described in its guidance on qualifying outbound links. They can be combined, for example rel="sponsored nofollow".
| Situation | Attribute | Notes |
|---|---|---|
| Adverts, paid placements, sponsored posts, affiliate links | rel="sponsored" (nofollow also acceptable) | Google says sponsored is preferred for paid links; unqualified paid links fall under its link spam policies |
| Links in comments, forums, reviews and user profiles | rel="ugc" (nofollow also acceptable) | Can be removed for trusted, consistently high-quality contributors |
| A source you need to reference but do not trust or want to vouch for | rel="nofollow" | For example, linking to a scam site in a warning article |
| Editorial links to sources you trust | None | Do not nofollow normal citations |
| Links between pages on your own site | None | Google recommends robots.txt rather than nofollow for keeping crawlers out of sections of your own site |
Google's spam policies specifically list "Text advertisements or text links that don't block ranking credit" and advertorials with links that pass ranking credit as link spam. If your business publishes sponsored content or runs affiliate links, our guides to dofollow, nofollow, sponsored and UGC and the affiliate and sponsored links audit explain how to get this right at scale.
Auditing outbound links for broken and risky destinations
Outbound links decay. Studies get moved, companies fold, domains expire and are bought by spammers. A link that pointed to a respected charity five years ago may now point to a casino site. A regular audit catches this.
- Crawl your site with a crawler set to check external links. In Screaming Frog, for example, external link checking is controlled in the crawl configuration; our Screaming Frog guide walks through it.
- Export all external links with source page, destination, status code and anchor text.
- Fix 4xx and 5xx errors by finding the new location of the resource, swapping to an archived or alternative primary source, or removing the link and adjusting the sentence.
- Review redirects to different domains. A redirect from a charity's old domain to an unrelated commercial site is a red flag that the domain has changed hands.
- Spot-check destinations by domain: sort by destination domain and open each one you do not recognise. Look for hacked pages, parked domains and gambling, adult or pharmacy redirects.
- Check attributes on paid, affiliate and user-generated links, and remove blanket nofollow from trusted editorial citations.
- Schedule the audit quarterly for large content sites and twice a year for smaller ones.
Worked example: a 300-post blog
This is a hypothetical example. A crawl of a 300-post marketing blog finds 2,140 external links to 610 domains. Of these, 148 return 404, 37 return 5xx errors, and 92 redirect to a different domain. Reviewing the 92 cross-domain redirects reveals six that now land on unrelated commercial sites, including two expired domains that have been turned into casino affiliate pages. The fix takes about eight hours: replace 120 broken links with current sources, remove 28 links where no good replacement exists, remove the six risky links immediately and add rel="sponsored" to 40 affiliate links that had been left unqualified. The blog's readers now land on working, relevant sources, and the site no longer points visitors to spam. Expired domains are a growing risk, as our guide to expired domains and SEO explains.
Questions content teams ask about linking out
Do outbound links pass PageRank away from my page?
They share what your page passes on, but they do not reduce the value your page receives from its own backlinks. Google says external links are nothing to be scared of and can help establish trust.
Should I nofollow all external links?
No. Google advises using nofollow only when you do not trust the source, and sponsored or ugc for paid and user-generated links. Normal editorial citations should be left as standard links.
How many outbound links should a page have?
There is no ideal number. Link where a reader would benefit from a source or further reading. A detailed guide may cite ten or more sources; a short service page may need none.
Is it bad to link to a competitor?
Not if their page is the best source for a claim. Citing it honestly makes your content more credible. If you would rather not, look for the primary source they used.
Should external links open in a new tab?
That is a usability decision, not an SEO one. Some sites open citations in new tabs so readers can return easily; accessibility guidance suggests telling users when a link will open a new window.
Setting an outbound linking policy for your content team
Write a one-page policy: cite primary sources for every statistic, link to the most specific supporting page, leave trusted citations as normal links, use sponsored for anything paid and ugc for user content, and audit external links on a schedule. Then fix the worst of your existing content, starting with the pages that get the most traffic. For the other side of the equation, earning links to your inner pages, see our guide to deep links.
If you want your content written and maintained to this standard, talk to our content writing and SEO teams, or get a free quote.
Further reading on outbound links seo
- Co-Citation and Co-Occurrence: Links and Mentions in Context
- Referring Domains vs Backlinks: Which Number Actually Matters?
- Deep Links: Why Links to Inner Pages Matter
- AI Hallucinated URLs: Fix 404s From ChatGPT and AI Referrals
Sources for this outbound links guide
- Link best practices for Google
- SEO Starter Guide – Google Search Central
- Qualify your outbound links to Google
- Spam policies for Google web search
- Are Outbound Links a Google Ranking Factor? – Search Engine Journal
- Long-term outgoing link experiment – Reboot Online
- Creating helpful, reliable, people-first content
- A guide to Google Search ranking systems
