Most toxic backlinks don’t require action, because Google often ignores low-quality links without affecting your rankings. But certain backlink patterns—especially ones tied to manipulative link building or obvious spam—can still trigger manual actions or weaken trust signals.
This guide explains what toxic backlinks are, why they happen, and how to identify them using automated tools and manual review. You’ll learn when link removal or disavowal makes sense so you can protect your site without creating new SEO risks.
What Are Toxic Backlinks?
Toxic backlinks are incoming links that can harm your website's visibility in search engine results pages (SERPs) when they form patterns that violate Google’s link spam guidelines. These links are typically created for SEO manipulation rather than genuine user benefit.
Google evaluates backlinks as part of how it determines your site's prominence and trustworthiness. Editorial, relevant links can strengthen SEO, while links created through manipulative tactics are often ignored or devalued by Google’s systems.
When manipulative backlinks appear at scale—or show clear signs of systematic link spam—they can still trigger a manual action for unnatural links. A manual action can suppress rankings or remove affected pages from search results until the issue is resolved.
But there is no universal or official definition of a toxic backlink. A link that looks suspicious in one context may be harmless—or even normal—in another, depending on your industry, site history, and overall backlink profile. This is why Google focuses on patterns of unnatural linking behavior, not individual links in isolation.
Google's stance on links intended to manipulate rankings is clear:
“Links obtained primarily for artificial manipulation of Search rankings are link spam. Our algorithms and manual actions aim to nullify these unnatural links at scale, and we will continue to improve our coverage.”
You can evaluate your backlink profile's overall risk with the Toxicity Score metric in Semrush's Backlink Audit tool, which flags links that may need closer review based on multiple risk markers.
How Does AI-Powered Search Change the Impact of Toxic Backlinks?
AI-powered search experiences—such as Google’s AI Overviews and tools like ChatGPT or Perplexity—often surface answers by evaluating authority, trust signals, and source credibility at a broader level than traditional rankings.
While Google’s algorithms may ignore many low-quality backlinks for ranking purposes, large or persistent patterns of manipulative links can still affect how trustworthy a site appears to AI systems.
In practice, this means backlink quality may influence whether a site is cited, summarized, or excluded in AI-generated answers. Keeping your backlink profile clean and well-contextualized helps protect rankings and visibility in AI-driven search results.
The Context-Dependent Nature of Toxicity
Toxic backlinks are contextual and often debated within the SEO community. A backlink that’s harmful for one site may be acceptable for another depending on the site’s industry, backlink profile, and intent.
For example, a backlink from a gambling-related site might be inappropriate for a children's education website but completely normal for a casino review platform. Similarly, foreign-language links might raise concerns for a local business but be expected for an international brand.
Tools like Semrush's Backlink Audit help surface potential warning signs by analyzing patterns across your backlink profile. But no tool can determine toxicity with complete certainty. Automated systems flag risk indicators, but human review is required to interpret intent and context accurately.
This is why experienced SEO professionals manually review flagged backlinks before taking action, rather than automatically disavowing every link a tool identifies as potentially harmful. In practice, understanding Google’s intent-based link spam guidelines matters more than treating backlinks as simply “toxic” or “safe.”
9 Common Sources of Toxic Backlinks
The practices below commonly lead to toxic backlinks, either by violating Google’s link spam guidelines or by creating link patterns that appear manipulative.
Some are intentional tactics, while others happen unintentionally—especially when link building isn’t closely monitored.
1. Paying for Links
Paying for backlinks isn’t always wrong—but paying for follow links that pass ranking value violates Google’s link spam guidelines.
If you exchange money, products, services, or any other compensation for a link, that link should be qualified so it doesn’t pass SEO value (PageRank). Google expects paid links to use a nofollow attribute, like one of the following options, in the link's HTML:
- rel="nofollow": Signals that Google should ignore the link for ranking
- rel="sponsored": Indicates the link was paid for and should be ignored for ranking
A properly qualified paid link looks like this:
<a href="https://example.com/" rel="nofollow">Anchor Text Here</a>The requirement to qualify paid links with nofollow or sponsored attributes applies to common marketing and partnership activities, including:
- Placing digital advertisements
- Gifting products in exchange for reviews
- Working with influencers
- Paying for directory listings
To review your existing links, check your follow backlinks using Semrush's Backlink Analytics tool.
Enter your domain and click "Analyze."
Go to the "Backlinks" tab, apply the "Follow" filter, and review whether any paid links are passing SEO value.
If you find paid follow links, contact the publisher and ask them to add the appropriate nofollow or sponsored attribute.
2. Exchanging Links for SEO
Link exchanges occur when two websites agree to link to each other primarily for SEO purposes rather than editorial value.
Occasional, natural reciprocal links aren’t inherently harmful. But excessive or systematic link exchanges can create unnatural link patterns, which may raise concerns for Google’s link spam systems.
If you’ve intentionally exchanged links at scale or as part of a structured SEO tactic, review those links carefully. Removing or qualifying links that exist only to manipulate rankings can help reduce risk—especially if the exchanges don’t reflect genuine partnerships or user value.
3. Engaging with Private Blog Networks
Private blog networks (PBNs) are groups of websites controlled by a single owner and used to pass backlinks to a target site (or sites).
Because PBNs exist primarily to manipulate rankings, Google actively works to detect them, and links coming from these networks carry a high risk of being ignored or treated as link spam.
If your site has backlinks from known or suspected PBNs, removing or disavowing those links is often the safest option, especially when they don’t provide real user value.
4. Using Link Building Bots
Link building bots are automated programs that generate backlinks at scale, often in user-generated content (UGC) areas (e.g., blog comments, forums, or profile pages).
Because these links are created without editorial judgment and usually follow repetitive, spam-like patterns, bot-generated backlinks are commonly treated as link spam. Be cautious of services that promise large numbers of backlinks quickly. They often rely on automation that creates more risk than value.
5. Posting Unnatural Links on Other Sites
Avoid adding unnatural backlinks to your own site—such as posting links in forums, comment sections, or social media threads solely for SEO purposes—because doing so reflects poorly on your brand and may be treated as link spam.
Google recommends qualifying UGC links with the rel="ugc" attribute. In many cases, these links are also marked as nofollow to signal that they shouldn’t pass ranking value.
You can see an example of a rel="ugc" link on Reddit:
Aggressive self-promotion in user-generated content spaces can also damage your brand beyond SEO. Forum moderators and community managers often monitor for patterns of self-promotional linking, and obvious spam can lead to deleted content, bans, or long-term negative associations with your brand.
If you participate in these platforms, focus on contributing genuine value first. When links are appropriate and allowed, qualify them with the rel="ugc" attribute to indicate user-generated content.
6. Listing Your Business on Low-Quality Directories
Listing your business in low-quality directories—especially those with little editorial oversight and a poor user experience—can produce toxic backlinks.
Directories that charge for listings deserve extra scrutiny. While paid listings aren’t automatically harmful, directories created primarily to sell links rather than serve users often produce risky backlink patterns.
Not all directories are problematic, but some are. As you build directory listings, focus on relevance, editorial standards, and user value.
7. Creating Widgets with Links
If you create an embeddable widget that links back to your site, any included links should be qualified with a nofollow attribute.
Embedded widgets (e.g., calculators, charts, price tickers, weather widgets, or other interactive tools) are copied and pasted onto third-party sites. Because the site owner doesn’t control the link’s placement, anchor text, or destination, Google doesn’t treat widget links as genuine editorial endorsements.
For example, TradingView's stock price widget includes a nofollow link back to its platform:
Without proper link attributes, widget links can appear manipulative, especially when they’re distributed at scale, because they artificially place backlinks across many sites without editorial choice. If you’ve already distributed widgets with follow links, update the embed code and ask users to replace older versions.
8. Mandating Backlinks Through Contracts
Google's spam policies state that requiring a backlink as part of a contract, terms of service, or similar agreement—without allowing the publisher to qualify the link—is considered link spam.
If your business has ever required backlinks through formal agreements, consider contacting partners or clients to ask that those links be removed or qualified with a nofollow or sponsored attribute.
You should also review and update contractual templates to ensure backlinks are optional and properly qualified when included.
9. Being the Victim of a Negative SEO Attack
Negative SEO refers to attempts to harm a site’s search performance, often by pointing large volumes of spammy backlinks at a domain in the hope of triggering a penalty.
In practice, Google says these tactics rarely cause lasting harm. John Mueller has repeatedly stated that Google’s systems are generally good at ignoring malicious or low-quality links created without a site owner’s involvement.
When asked about negative SEO on Reddit, Mueller responded:
But some SEO professionals report different experiences in practice, particularly when sudden spikes in spammy backlinks coincide with ranking drops or manual action. This is why monitoring unexpected backlink surges remains a common best practice, rather than relying entirely on automated systems to resolve the issue.
How to Find Toxic Backlinks
Google usually ignores isolated low-quality backlinks. But you should actively check for toxic backlinks if you’ve engaged in link building in the past, notice unexplained ranking drops, or receive a manual action for unnatural links.
To see whether Google has applied a manual action, sign in to Google Search Console.
Navigate to "Security & Manual Actions" > "Manual actions."
If you see "No issues detected," that’s a good sign. But reviewing your backlink profile can help you identify risky patterns early—especially if you’re unsure how some links were created.
If your site does have a manual action for unnatural links, you’ll need to identify the problematic backlinks and address them promptly to recover visibility.
Use one of the two options below to find potentially toxic backlinks.
Use a Toxic Backlink Checker
A toxic backlink checker helps you quickly surface backlinks that may pose a risk, based on known spam signals and link patterns. These tools don’t make final judgments but are the fastest way to prioritize links for review.
Semrush's Backlink Audit tool is one option.
Enter your domain and click "Start Backlink Audit."
Follow the setup instructions.
Once the audit finishes, you'll see your "Overview" report.
If you have Google Analytics, Google Search Console, or Majestic accounts, connect them under "Integrations" to improve accuracy.
To review individual links, go to the "Audit" report.
The tool evaluates backlinks against dozens of toxic markers and assigns each one a Toxicity Score (TS) from 0-100. Higher scores indicate links that are more likely to be risky—not links that are automatically harmful.
Click a Toxicity Score to see which markers were triggered and whether they're labeled "Dangerous" or "Potentially dangerous."
Check the "Anchor" column, which shows the backlink's anchor text and category.
Risky backlinks often use:
- Money anchor text, which exactly matches a target keyword (e.g., "best running shoes")
- Compound anchor text, which combines a brand name with a keyword (e.g., "amazon running shoes")
These anchor types are more likely to signal SEO-driven placement rather than editorial intent.
In the "AS" column, review the referring domain's Authority Score (AS)—a 0-100 metric that reflects the domain's overall authority. Higher scores generally indicate lower risk.
To inspect a backlink directly, click the icon next to the source URL.
Use all of this information together—context, patterns, anchors, and authority—to decide whether a backlink is actually risky for your site.
- If the link looks safe, click "Move to Whitelist"
- If it looks manipulative or harmful, click "Move to Remove list"
Check Toxic Backlinks Manually
Manually reviewing backlinks is slower than using a backlink checker, but it gives you direct visibility into where links come from and how they’re placed, which can be useful if you want full control over the evaluation process.
To see which sites link to you, open Google Search Console.
Go to "Links" in the left-hand menu. Under "Top linking sites," click "More."
Export the list of referring sites.
Open the file in a spreadsheet and review backlinks individually, looking for patterns that may indicate manipulation, such as irrelevant domains, spammy pages, or unnatural anchor text.
Keep in mind that Google Search Console shows a limited sample of your backlinks, which makes this process time-consuming and incomplete. To prioritize your review, Google recommends starting with domains that link to you most frequently or focusing on recently created links.
How to Remove Toxic Backlinks
Once you’ve identified a backlink that appears genuinely manipulative or harmful, the first step is to request removal or proper link qualification from the referring site.
If removal isn’t possible, disavowing the link may be appropriate. But only in specific situations, like when you have a manual action or a clear pattern of unnatural links.
Below are the two approaches and when to use each.
How to Request Link Removals
Requesting link removal is the preferred first step when dealing with toxic backlinks. It’s slower than disavowing, but it’s also the cleanest way to resolve problematic links—especially when a real site owner is involved.
Follow the Backlink Audit workflow described above, then open the "Remove" report to view backlinks you’ve flagged for removal.
Click "Add" next to "Mailbox:" and connect your business email account. This lets you send outreach emails directly from your company address.
Choose a backlink to address. Backlinks are sorted by Toxicity Score, so it’s usually best to start with the highest-risk links first.
To contact the referring site, look for an email address or contact details. Backlink Audit may surface links to the site's contact page or social profiles beneath the domain information.
When you're ready, click "Send" to open the email editor.
A message template with placeholders will appear. In your email, briefly explain:
- Where the backlink is located
- That you’re requesting removal or qualification
- Why the link may violate Google’s guidelines
Keep the message concise, clear, and polite. Short, neutral requests are more likely to get a response.
Click "Send and proceed to next" to continue working through your list of backlinks.
After sending, monitor the "Status" column to check whether your email has been sent, delivered, opened, or replied to.
Use the icon in the "Access link" column to check whether a backlink has been removed.
If you don’t receive a response after a reasonable follow-up period—or if links can’t be removed—disavowing may be appropriate, which we’ll cover next.
How to Disavow Toxic Backlinks
Proceed with caution: Disavowing backlinks is a powerful but often misused tactic. Google generally recommends using the disavow tool only when you have a manual action for unnatural links or clear evidence of past manipulative link building. In many cases, disavowing links unnecessarily can do more harm than good.
Disavowing links means asking Google to ignore specific backlinks so they don’t influence your site’s search performance. It’s a powerful but risky action, and Google advises against using it unless there’s a clear reason.
According to Google, disavowing links generally makes sense only when both of the following apply:
- Your site has a manual action for unnatural links
- You’ve previously participated in manipulative link-building practices, like buying links
Even then, disavowal should be used cautiously. At Pubcon Austin 2023, Google's Gary Illyes noted that disavow files can sometimes do more harm than good when they’re used unnecessarily or too broadly.
If you decide to proceed, start in Backlink Audit by opening your “Remove” list. Select the backlinks you want to disavow, then click the “Disavow” icon.
In most cases, it’s better to disavow at the domain level rather than the individual URL level.
Domain-level disavows help cover duplicate or future URLs on the same site (e.g., "example.com/toxic-page" and "example.com/toxic-page.html") and reduce the chance of missing related links.
After finalizing your list, go to "Disavow" and click "Export to TXT."
Upload the .txt file to Google's disavow tool.
Once uploaded, return to Backlink Analytics and click "Yes, I uploaded the file" so the tool can recalculate your site's Toxicity Score.
If your site has a manual action, submit a reconsideration request in Google Search Console using the “Request review” button in the Manual Actions report.
Disavowal effects aren’t immediate. It may take several weeks for Google to process the file and even longer to see any impact on your SEO results.
Real-World Toxic Backlink Examples
Real-world toxic backlink examples help you spot risky patterns in context.
The scenarios below reflect situations SEO professionals commonly encounter when reviewing backlink profiles, and show when intervention may actually be necessary.
Sudden Directory Link Spikes
A financial services company discovered 500+ new backlinks appearing over a single weekend, all from low-quality business directories across Eastern Europe and Asia. These directories had minimal traffic, poor user experience, and were filled with unrelated listings.
The toxicity markers included foreign-language anchor text, exact-match commercial keywords, and IP address clustering. Taken together, these signals pointed to a coordinated, unnatural link pattern, followed by a 40% drop in organic visibility within two weeks.
After attempting (and failing) to contact directory owners for link removal, the team used Google's Disavow Tool to reject the links in bulk. In this case, disavowal was a last-resort cleanup step, not the first response.
Negative SEO Attack
Ranking declines were the first warning sign for an ecommerce retailer that hadn’t changed its link building strategy. Investigation revealed 1,000+ spammy backlinks appearing within a short time frame, coming from adult content sites, pharmaceutical forums, and known link farms.
Many of these links used over-optimized anchor text matching the site’s primary target keywords and appeared within days of each other—signals consistent with an unnatural backlink pattern. Google applied a manual action for unnatural links shortly after.
After documenting the timeline and showing that the links weren’t created by the site, the team submitted a reconsideration request along with a comprehensive disavow file. Rankings recovered within 45 days.
Hacked Website Backlinks
Not all toxic backlinks come from obviously low-quality sites. In this case, a SaaS company uncovered hundreds of backlinks coming from legitimate, high-authority websites that had been compromised by hackers.
These sites contained hidden footer links, injected spam pages, or malware that linked out to multiple unrelated domains, including the company’s site. Toxicity markers included hidden text, irrelevant anchor text on otherwise trusted domains, and links from pages that didn't exist in the site's normal navigation.
To resolve the issue, the team identified affected webmasters and notified them of the security breaches. Links that couldn’t be removed in a reasonable time frame were disavowed to limit further impact.
Expired Domain Redirects
After acquiring what appeared to be a clean domain, a healthcare company later discovered it had inherited toxic backlinks from the domain’s previous use in a private blog network (PBN) scheme. Before the acquisition, the domain had redirected to dozens of unrelated sites, leaving behind a history of manipulative linking.
The toxicity surfaced through irrelevant referring pages, mismatched anchor text from unrelated industries, and backlinks from networks of sites using identical templates. Although the new owner’s site was legitimate, these historical link patterns continued to affect the domain’s backlink profile.
To address the issue, the team reviewed historical backlink data, disavowed suspicious patterns tied to the previous owner's activity, and focused on earning fresh, relevant backlinks to rebalance the link profile.
You can use toxic markers in Backlink Audit to spot similar patterns in your own backlink profile and decide whether cleanup is necessary.
Strengthen Your Backlink Profile with Semrush
Strengthening your backlink profile goes beyond removing toxic links. Long-term SEO stability comes from earning relevant, editorial backlinks that reflect genuine authority and trust, not from constant cleanup.
If you’re building links intentionally and monitoring your backlink profile regularly, occasional low-quality links are less likely to become a problem.
As a next step, use Backlink Analytics to regularly review your backlink profile, track new referring domains, and spot unusual patterns early.
By focusing on quality, relevance, and consistency, you reduce the risk of toxic backlinks and can spend less time fixing issues later.