Black Hat Link Building: What It Really Is (and What It Isn't)

At a glance

• Black hat link building means getting links by abusing other people’s websites: hacking them, spamming their comments and forums, or hiding links on pages you don’t own.
• Most articles define black hat as “anything Google doesn’t like”, which puts paid guest posts and link exchanges on the same side of the line as PBNs.
• A private blog network you build on your own domains is against Google’s guidelines, so call it grey hat if you like. It is not black hat, because it’s your property.
• Google says it uses SpamBrain to neutralize unnatural links, so most spam links end up ignored rather than punished.
• Negative SEO is black hat link building pointed at a competitor instead of at your own site.

The usual definition is “any link building that breaks Google’s rules.” It’s convenient for the people who publish it, many of whom sell links themselves. It lets paid guest posts sit on the white side and puts PBNs on the black side, even though Google’s spam policies list both.

Black hat, grey hat and white hat: a better line

Two separate questions get mixed up here. Does the tactic break Google’s spam policies? And whose property does it use? The first question is about Google’s search results. The second is about whether you’re harming someone.

Tactic	Whose property	Against Google’s spam policies?	Our label
Injecting links into hacked sites	Someone else’s	Yes (hacked content)	Black
Comment and forum spam	Someone else’s	Yes (user-generated spam, link spam)	Black
Automated mass link software	Someone else’s	Yes (“automated programs or services”)	Black
Hidden links	Usually someone else’s	Yes (hidden text and link abuse)	Black
Negative SEO against a competitor	Someone else’s	Yes	Black
Scraped or spun content sites built to hold links	Your own	Yes (scaled content, link spam)	Grey, and poor quality
Link farms	Usually your own	Yes	Grey, and easy to catch
Buying links that pass ranking credit	The seller’s, with consent	Yes	Grey
Paid guest posts	The publisher’s, with consent	Yes, if the link passes credit	Grey
Excessive link exchanges	Both sites, with consent	Yes	Grey
Your own PBN	Your own	Yes	Grey
Outreach and broken link building	The publisher’s, with consent	No, unless money or a link swap changes hands	White

Google’s spam policies (fetched 2026-10-28) list as link spam “Exchanging money for links, or posts that contain links”, “Excessive link exchanges”, “Using automated programs or services to create links to your site”, and “links with optimized anchor text in articles, guest posts, or press releases distributed on other sites.” By Google’s own list, a paid guest post with a keyword anchor breaks the same policy as a PBN link.

Our PBN guide makes the same point: PBNs are against Google’s guidelines, but so are buying links and even popular “white hat” options like outreach and guest posts. Breaking a search engine’s guidelines is a business risk. Breaking into someone’s website is a different thing, and that’s what earns the black hat label.

The real black hat techniques

Hacked-site link injection

Attackers get into a site through an outdated plugin or a weak password and add links or whole pages. Google’s spam policies define hacked content as “any content placed on a site without permission, due to vulnerabilities in a site’s security”, and name code injection, page injection and content injection as examples.

This is black hat in the plain sense: it uses someone else’s property without permission. The site owner cleans it up, Google flags the pages, and the links disappear.

Comment and forum spam

Bots or people drop links into blog comments, forum threads and signatures. Google’s spam policies list “Comment spam on blogs” and “Spammy posts on forum threads” as user-generated spam, and give “Forum comments with optimized links in the post or signature” as an example of link spam.

Most platforms add nofollow to user links, and many delete spam on sight. What survives is a link on a page full of other spam links, which is worth very little.

Automated link-building software

A category of desktop tools posts links on autopilot. You give them a list of keywords and URLs, and they find blogs with open comments, forums, profile pages and free web 2.0 blogs, register accounts and post links at a rate of thousands a day.

The links are mostly low value. These tools target platforms that are open to anyone, and those platforms have been spammed to death by everyone else running the same software. Many of the links are nofollow, sit on pages nobody visits, or get deleted by moderators.

Some SEOs still use these tools for a narrow job: pointing low-quality links at their own lower-tier links, press releases or business citations to get those pages crawled and indexed. That’s the logic of tiered link building, where cheap links point at better links instead of at your main site. Our view is that it isn’t worth it. You’re adding a pile of spam to the web to speed up indexing that usually happens anyway, and anything traceable back to you is a risk you didn’t need.

Pointing this software straight at a money site is the worst use of it.

Hidden links

White text on a white background, a link on a single character, or text pushed off-screen with CSS. Google’s spam policies list all of these under hidden text and link abuse. On your own site it’s just a bad idea. Planted on someone else’s site, usually through a hack or a compromised theme or plugin, it’s black hat.

Link farms vs PBNs

A link farm is a set of sites that exist only to hold links. They link to each other and to anyone who pays, carry thin or scraped content, and often share hosting, templates and ownership details. They’re cheap to build and easy to spot, and they get deindexed as a group.

A private blog network built properly differs on each of those points. Each blog sits on an expired domain that already has its own backlinks, restores or rebuilds the old site’s content, adds new articles, and looks like an ordinary niche site. The owner links only to their own sites and never sells links on it. Our PBN guide’s test for anything you’re unsure about is simple: would it be natural for a legitimate blog?

So are PBNs black hat? No. They’re against Google’s guidelines, and we say so plainly. But they’re built on domains you bought, hosted on servers you pay for, with content you wrote. Nobody else’s property is involved. If you want the full picture, start with what a PBN is.

The risk is real but manageable. The networks that get deindexed are usually the ones with footprints: the same owner details on every domain, the same hosting, or links that only ever point at the same few money sites. Avoid those and the main risk goes away.

Does black hat link building still work?

Mostly, no, and the reason is less dramatic than the warnings suggest. Old posts on this topic said you’d be “penalized and possibly banned from Google.” Usually the links just stop counting.

In its December 2022 link spam update post, Google said it was using SpamBrain, its AI spam-prevention system, “to neutralize the impact of unnatural links on search results.” It said SpamBrain “can now detect both sites buying links, and sites used for the purpose of passing outgoing links”, and that “Ranking may change as spammy links are neutralized and any credit passed by these unnatural links are lost.”

That’s Google describing its own systems, so read it as Google’s claim. In practice it matches what you’d expect. Comment spam, forum spam and automated links sit on platforms Google has seen abused for years, so they’re the easiest links to discount. You pay for them in time, software or money, and they pass nothing.

Manual actions still happen. Google’s spam policies say violations are caught “both through automated systems and, as needed, human review that can result in a manual action”, and that sites that violate the policies “may rank lower in results or not appear in results at all.” If that happens, it shows up in Search Console under Manual actions.

Negative SEO: black hat aimed at you

Negative SEO is the same toolkit pointed at a competitor: thousands of spammy links, often with adult, pharma or casino anchors, sent to someone else’s site in the hope that Google punishes it. By our definition it’s black hat twice over, because it uses other people’s sites to place the links and targets another business.

If Google’s systems ignore most spam links, they mostly ignore these too. Still, check your backlink profile now and then in Ahrefs, Semrush or Search Console. Our guide to toxic backlinks covers when bad links can hurt and what to do about them.

What to do instead

If you want links you control, build them on property you own. That means buying expired domains with real backlinks, restoring and adding content, hosting the blogs so they don’t share footprints, and linking to your own sites sparingly. Our guide to build your own network walks through it, and you can host your blogs on Easy Blog Networks, where each blog gets its own IP and nameservers from a different hosting provider.

If you’d rather earn links from other people’s sites, do it with their consent. Broken link building is plain outreach, nothing black hat about it: you find a dead link on someone’s page and suggest your page as a replacement. Our broken link outreach templates show how.