Are External Links Good for SEO? How Linking Out Really Works

Yes, external links are good for SEO when they point to relevant, trustworthy pages that help the reader. Google's documentation does not present linking out as a direct ranking boost. What its SEO Starter Guide does say is that links can give users and search engines more context on a topic, which may help demonstrate your knowledge, as long as you trust the page you link to.

So if you have been asking "are external links good for SEO" because someone told you linking out "leaks" ranking power, you can relax. The real risks sit elsewhere: paid links without the right attribute, links to spammy or broken pages, and pages that become link directories with little content of their own. This guide covers how outbound links work, when to qualify them, how many is too many, and how to keep them healthy over time.

What an external link is, and how it differs from a backlink

An external link (also called an outbound link) is a link on your page that points to a different domain. If your article on Thai VAT rules links to the Revenue Department website, that is an external link from your point of view.

A backlink, or inbound link, is the same link seen from the other side. For the Revenue Department, your link is a backlink. Every link on the web is outbound for one site and inbound for another.

The distinction matters because the two do different jobs in SEO:

• Inbound links are one of the signals search engines use to judge how important and trusted a page is. Earning them is the work of link building and digital PR.
• Outbound links are mainly about the quality of your own page. They show where your facts come from, point readers to deeper material, and help search engines understand what your page is about by the company it keeps.
• Internal links point to other pages on your own domain. They spread authority around your site and help crawlers find your content. They are a separate topic and not covered here.

Most worry about outbound links comes from mixing these up. People hear that links pass ranking value and assume that every link they give away is value they lose. That is not how modern search works.

Does linking out help or hurt rankings?

Linking out to good sources does not hurt your rankings, and it can help indirectly. The old idea of "PageRank hoarding", where sites refused to link anywhere so as to keep all their authority, does not match Google's current advice. Its SEO Starter Guide tells site owners to link when it helps, and to add nofollow or a similar annotation only when they can't trust the page they are linking to.

What Google has said consistently is that it wants pages that are helpful, reliable and made for people. Its guidance on creating helpful content asks questions such as whether the content provides substantial value and whether it presents information in a way that makes you want to trust it. Citing a primary source is one of the clearest ways to answer that question for a reader.

Here is how outbound links can help:

1. Topic context. Google's SEO Starter Guide says links can provide more context on a topic for users and search engines. A page about Google Ads bidding that links to Google's own help article on Smart Bidding gives readers that context, and descriptive anchor text tells both readers and Google what the linked page contains.
2. Reader trust. A statistic with a link to the original report can be checked. A statistic with no source cannot.

And here is how they can hurt:

• Linking to sites that break Google's spam policies, such as hacked pages, scraped content or link farms.
• Selling links that pass ranking credit, or taking part in large-scale link exchanges. Google's spam policies name both as link spam.
• Filling a page with so many links that the content becomes hard to find, which is a user experience problem before it is an SEO one.
• Letting links rot until readers keep hitting dead pages.

Each of these is a problem with linking out badly, not with linking out.

When to use nofollow, sponsored or ugc on outbound links

Use a rel attribute when you need to tell search engines something about your relationship with the page you link to. In September 2019 Google added sponsored and ugc alongside nofollow and began treating all three as hints for ranking rather than strict commands. From 1 March 2020, nofollow also became a hint for crawling and indexing:

• rel="sponsored" for links that are paid for, part of an affiliate deal, a sponsorship or any other exchange of value.
• rel="ugc" for links inside user-generated content, such as comments and forum posts.
• rel="nofollow" for other cases where you don't want to vouch for the page or pass ranking credit, for example a link to a site you are criticising.

A normal editorial link, where you chose to cite a page because it is useful, needs no attribute at all. Adding nofollow to every outbound link "to be safe" is a common habit, but it removes the endorsement you meant to give and tells search engines nothing useful about your page.

The one rule that is not optional: if money, free products or any other value changed hands for a link, qualify it with sponsored (Google prefers it, though nofollow is still acceptable). Google's spam policies treat paid links that pass ranking credit as link spam, and that can lead to manual action against the site that sells them.

How many outbound links are too many?

There is no fixed number, and Google does not publish one. Its SEO Starter Guide frames the question around usefulness: link when it gives readers more context, and make sure you trust the page you link to.

A better test is purpose. Ask of each link: does this help the reader understand or verify something on this page? A 2,000-word guide citing eight official sources is normal. A 300-word page with forty links to unrelated sites looks like a link directory or a link scheme, and readers will treat it as one.

Some practical guidelines that work in most cases:

• Link to the primary source, not to a blog that summarises it. If a figure comes from a government report, link the report.
• Link once per source per page, at the first point you use it, unless the page is very long.
• Use descriptive anchor text such as "the Bank of Thailand payment statistics" rather than "click here".
• Keep outbound links out of footers and sidebars sitewide unless there is a real reason, because a link repeated on every page tends to look like a deal rather than a citation.

Opening external links in a new tab: does it matter for SEO?

Opening links in a new tab has no direct effect on SEO. Search engines read the href and the rel attribute, and target="_blank" is neither. Whether to use it is a user experience choice.

The argument for a new tab is that the reader keeps your page open. The argument against is that it takes control away from the user, can confuse people using screen readers, and breaks the back button. Accessibility guidance generally recommends warning users when a link opens a new window.

There used to be a security reason to add rel="noopener" alongside target="_blank", because the new page could otherwise access and redirect the original tab. Current versions of the major browsers now apply noopener behaviour to target="_blank" links by default, but adding it explicitly does no harm and protects older browsers. It has no ranking effect either way.

Broken outbound links and how to find them

A broken outbound link points to a page that no longer exists or returns an error. One broken link will not cost you rankings on its own, but a page full of them signals neglect, frustrates readers and wastes the trust the links were meant to build.

External pages break more often than you might expect. Government agencies reorganise their sites, companies rebrand, reports move to new URLs and blogs shut down. An older article can lose a large share of its citations without anyone on your team noticing.

Google Search Console does not report broken outbound links, because it reports on your own URLs. To find them you need a crawler:

1. Run a site crawl with a tool such as Screaming Frog SEO Spider, Sitebulb or the site audit in Ahrefs or Semrush, with external link checking turned on.
2. Filter for external links that return 4xx or 5xx status codes, plus redirects that end somewhere unrelated.
3. For each one, find where the content moved. Search the publisher's site, or check an archived copy to confirm what the original page said.
4. Replace the link with the new URL, swap in a better current source, or remove the link and the claim if no source survives.
5. Repeat the crawl on a schedule. Quarterly suits most business sites; monthly suits large publishers.

Redirected outbound links are less urgent than broken ones, but a redirect that now lands on a homepage or a different topic is effectively broken for the reader and worth fixing.

Linking to sources as an E-E-A-T trust signal

E-E-A-T stands for experience, expertise, authoritativeness and trust. It comes from Google's Search Quality Rater Guidelines, the document Google gives to human raters who evaluate search results. Raters don't change rankings directly; their feedback helps Google test whether its systems surface reliable content.

The guidelines put trust at the centre and ask raters to consider whether a page is accurate and whether its claims can be supported. Outbound links to strong sources are one visible way to show that support. They are not a switch that turns on E-E-A-T, and a weak page full of links to Wikipedia will not become trustworthy because of them. But on topics where accuracy matters, such as tax, law, health and finance, a page that shows where its facts come from is much easier to trust than one that asks readers to take its word for it.

Good candidates for outbound citations include:

• Official documentation from the platform you are writing about, such as Google Search Central or Meta Business Help Center.
• Government and regulator sites for rules, rates and legal requirements.
• Original research reports, linked at the report page rather than at a news story about it.
• Standards bodies and recognised industry associations.

Outbound link checklist

The table below sums up the main outbound link decisions and what each one does for a page.

What this means for Thai businesses

For Thai-language websites, the biggest gain usually comes from linking to Thai primary sources rather than to English summaries. If an article explains a rule from the Revenue Department, the Department of Business Development or the Bank of Thailand, link to the page on that agency's own .go.th or .or.th domain. Thai readers recognise these domains, and the link shows that the claim comes from the authority itself.

Bilingual sites should check that each language version cites sources in the same language where one exists. An English page can link to an English version of a government notice, while the Thai page links to the Thai original. Where only a Thai source exists, it is fine to link to it from the English page and say so in the sentence.

Thai businesses that pay for placements on news sites or blogs should also check how those links are marked. A paid article that links back to your site should use rel="sponsored". Asking a publisher to remove it is asking them to break Google's guidelines, and the risk then sits with both sites. If you want to grow inbound links in a way that holds up, the work belongs in a proper link building service rather than in paid posts with followed links.

If your site has years of content, an SEO audit that includes an outbound link check is a quick way to find dead citations and paid links that were never marked. It fits naturally alongside the wider technical and content work in an SEO programme for the Thai market.

FAQ: external links and SEO

Are external links a Google ranking factor?

Google's documentation does not list linking out as a direct ranking factor. Its SEO Starter Guide says links can give users and search engines more context on a topic, and its guidance on helpful content asks whether content shows clear sourcing.

Do external links pass PageRank away from my site?

A followed link can pass some ranking signal to the page you link to, but Google's SEO Starter Guide still encourages linking to trusted pages where it adds context. Refusing to link to good sources to "save" authority makes pages worse for readers and gains nothing.

Should all external links be nofollow?

No, only paid, sponsored, user-generated or untrusted links need a qualifying attribute. Normal editorial citations should be plain links, because the point of citing a source is to vouch for it.

How often should I check for broken outbound links?

Quarterly works for most business websites, and monthly for large content sites. Run a crawler with external link checking switched on, because Google Search Console will not list broken links that point to other domains.

Outbound links are a small part of SEO, but they are one of the easiest places to show readers and search engines that your content is careful. If you want a second pair of eyes on how your site links out, and in, Relevant Audience can review it as part of an SEO audit and tell you what to fix first.