Before partnering with another website for guest posts, link exchanges, or co-marketing, it’s crucial to vet their credibility, security, and SEO health. A poorly maintained site can harm your rankings, expose you to security risks, or damage your brand’s reputation. Fortunately, you don’t need a big budget to conduct a thorough audit. Here are the top 5 free tools to evaluate a website’s health and ensure safe, fruitful collaborations.
1. Google PageSpeed Insights
What It Does: Analyzes website speed and performance across mobile and desktop.
Why It Matters: Slow sites frustrate users, hurt SEO rankings, and signal poor technical maintenance.
How to Use It:
- Enter the website’s URL.
- Review the performance score (0–100) and Core Web Vitals (LCP, FID, CLS).
- Check recommendations like optimizing images or reducing JavaScript.
Red Flags:
- Scores below 50 (needs improvement).
- “Poor” ratings in Core Web Vitals.
2. SSL Checker by SSL Labs
What It Does: Tests SSL/TLS certificate validity, encryption strength, and vulnerabilities.
Why It Matters: SSL ensures data security. Outdated certificates or weak encryption can expose user data.
How to Use It:
- Visit SSL Labs’ SSL Test.
- Enter the domain.
- Review the grade (A+ to F) and warnings (e.g., expired certificates).
Red Flags:
- Grades below A.
- Expired certificates or insecure protocols (SSLv3, TLS 1.0).
3. Ahrefs Backlink Checker
What It Does: Reveals a site’s backlink profile, including spammy or toxic links.
Why It Matters: Collaborating with sites linked to spam can harm your SEO via “guilt by association.”
How to Use It:
- Go to Ahrefs Backlink Checker.
- Enter the domain.
- Check the “Referring Domains” list for suspicious sites (casinos, adult content).
Red Flags:
- High percentage of links from unrelated niches.
- Toxic Backlinks score above 10% in Ahrefs’ report.
4. Ubersuggest
What It Does: Provides SEO metrics like domain score, organic traffic estimates, and keyword rankings.
Why It Matters: Gauges a site’s SEO authority and potential traffic value.
How to Use It:
- Visit Ubersuggest.
- Enter the domain.
- Review Domain Score (0–100), top keywords, and traffic trends.
Red Flags:
- Domain Score below 30.
- Plummeting organic traffic or keyword rankings.
5. BuiltWith
What It Does: Identifies the technology stack, CMS, and plugins used by a website.
Why It Matters: Outdated software (e.g., WordPress 4.0) can indicate security risks.
How to Use It:
- Visit BuiltWith.
- Enter the domain.
- Check the CMS, hosting provider, and plugins (e.g., abandoned jQuery libraries).
Red Flags:
- Unsupported CMS versions.
- Reliance on deprecated plugins or frameworks.
Bonus: Google Safe Browsing
What It Does: Checks if a site is flagged for malware, phishing, or harmful content.
How to Use It: Visit Google Safe Browsing, enter the URL, and confirm it’s marked “No unsafe content found.”
How to Use These Tools Together
- Start with Security: Use SSL Checker and Google Safe Browsing to rule out risks.
- Evaluate SEO Health: Check Ahrefs for toxic links and Ubersuggest for domain authority.
- Assess Technical Quality: Run Google PageSpeed Insights and BuiltWith to spot speed or tech issues.
Real-World Example
A marketer considering a guest post partnership used these tools to uncover:
- SSL Checker: The site had an expired SSL certificate (Grade F).
- Ahrefs: 40% of its backlinks came from spammy directories.
- PageSpeed Insights: Mobile speed score of 32.
Result: They avoided a risky collaboration and found a better partner through SEO Collabs.
Conclusion
Spending 10 minutes with these free tools can save you from SEO penalties, security breaches, or wasted efforts. Whether you’re vetting a link exchange partner or a co-marketing ally, prioritize sites that are fast, secure, and ethically optimized.

Ready to Find Vetted Partners?
Platforms like SEO Collabs pre-screen collaborators, but pairing them with these audits ensures bulletproof partnerships.
About SEO Collabs: A secure platform for ethical link-building. Connect with verified websites, automate audits, and grow your SEO with confidence.