Is interlinking multiple web projects risky for SEO?

Does Google consider all links between sites to be spam?

No, and this is an important nuance. Google does not condemn links between projects you own by principle. What matters is the intent and the extent of the setup.

If you manage two complementary sites and make a natural contextual link between them, Google will not penalize you. The engine aims to detect artificial site networks created solely to manipulate PageRank, not to sanction any legitimate connection between web properties.

What qualifies as a massive link network according to Google?

This is where the statement remains deliberately vague. Google does not provide any numerical thresholds: no "maximum of 3 links per site" or "no more than 5 interconnected domains."

In practical terms, issues typically arise when the linking becomes systematic and illogical. For example, 15 thematically unrelated sites that all link to each other in the footer, or dozens of domains that consistently point to a "main site" without providing added value for the user.

Why does Google recommend focusing on fewer projects?

Because it’s an operational reality before being an algorithmic directive. Properly managing a site requires regular content, quality backlinks, a polished user experience, and technical maintenance.

Multiplying projects without having the resources to manage them effectively often leads to zombie sites: thin content, poor internal linking, and mediocre user signals. These sites don't rank, and the links they send carry no value. Therefore, Google suggests streamlining to focus your time/money budget on properties that can actually perform.

• Links between sites you own are not prohibited by nature
• The notion of a "massive network" is subjective and context-dependent
• Google prioritizes the individual quality of projects over interconnected quantity
• A single contextual link between two complementary sites poses no issue
• The risk increases with systematic linking and without editorial justification

Is this position consistent with observed practices on the ground?

Yes, overall. It is indeed seen that small networks of sites (2-3 well-managed projects with a few relevant cross-links) generally encounter no issues. On the other hand, massive PBNs (Private Blog Networks) are regularly detected and downgraded.

But be careful, the line is sometimes very thin. I've seen legitimate projects with 4-5 related thematic sites suddenly lose positions after an update, without being able to clearly identify if it was linked to inter-site linking or other factors. [To verify]: Does Google have automatic indicators to detect common ownership across several domains? Officially no, but behavioral patterns (same hosting, same Analytics, same link schemes) can create signals.

What are the gray areas that Google does not clarify?

Several points remain deliberately vague. How many links between two sites is considered "excessive"? Does a footer link count as much as a contextual link? Does the common theme between the sites play a role in assessing "naturalness"?

Google will never precisely answer these questions, because it would allow people to game the system. As a result, you must navigate on instinct. My experience shows that footer/sidebar links between sites of the same owner are the most risky, while occasional contextual links in editorial content fare better.

In what cases does this rule not really apply?

Large media and press groups regularly link between their various brands without any reaction from Google. Le Monde, Prisma Media, Webedia: they have dozens of sites that cite each other.

The difference? These sites have established editorial authority, direct traffic, and massive external mentions. Google treats them differently from a micro-network of self-produced blogs. Is it unfair? Maybe. Is it the reality? Absolutely. If your project lacks this stature, the rules are stricter for you.

What should you do if you manage multiple sites?

First, audit your current linking. List all the links between your different properties: how many, where (footer/sidebar/content), with what anchor, what editorial justification. If you notice a systematic pattern (all your sites link to the "main" from the footer), it's a red flag.

Then, streamline. Keep only the links that provide real value to the user. For example: a blog post A that naturally cites a complementary resource from site B is legitimate. A "Our other sites" link in the footer without context smells of manipulative SEO.

What errors should you absolutely avoid?

Do not create automatic reciprocal link schemes between all your sites. This is the typical pattern of PBNs, and Google easily detects it. Also, avoid over-optimized anchors: if all your sites use exactly the same anchor to link to your main site, it's suspicious.

Another common mistake: maintaining inactive sites just to pass link juice. A site without recent content, without traffic, without external backlinks, existing solely to link to your main project is exactly what Google aims to neutralize.

How can you check if your setup is healthy?

Ask yourself the editorial question: if tomorrow you had to justify every link to a quality rater, can you explain its user relevance? If the answer is "it's for SEO", you have a problem.

Also check the diversity of your backlinks. If 80% of your links come from sites you own, your profile is unbalanced. A healthy site receives most of its links from external sources over which you have no control.

• Audit all links between your different web projects
• Remove systematic footer/sidebar links without editorial value
• Only keep justified contextual links for the user
• Diversify your anchors and avoid repetitive patterns
• Prioritize investment in 2-3 sites instead of spreading your resources
• Obtain external backlinks to balance your link profile