Best practices for setting up Canddi tracking across multiple domains

If you’re reading this, you’re likely juggling more than one website and want to track visitors across all of them without ending up with a mess of duplicate visitors or broken journeys. Setting up Canddi tracking across multiple domains sounds simple enough—until you actually try it. Here’s how to get it right the first time, avoid the gotchas, and keep your analytics useful.

Who’s this for?

  • You run or manage two or more websites (your main site, a landing page, maybe a sub-brand).
  • You care about seeing real user journeys, not just page views.
  • You want actual, actionable visitor data—not vanity numbers.

If you’ve ever looked at your analytics and thought, “Wait, why does the same person show up twice?”—this guide is for you.

Step 1: Know How Canddi Handles Tracking

Before you start copying and pasting code, take a minute to understand what Canddi actually does with its tracking.

  • Canddi is cookie-based. It drops a first-party cookie to track visitors.
  • By default, cookies are domain-specific. So, if Jane visits siteA.com and then siteB.com, Canddi will treat her as two people—unless you jump through some hoops.
  • Cross-domain tracking isn’t automatic. You need to set it up. Don’t believe anyone who says “just add the script everywhere and you’re good.”

Pro tip: If you only have subdomains (like blog.yoursite.com and www.yoursite.com), Canddi can usually track across them with minor tweaks. Full-blown cross-domain tracking (completely different root domains) is another story.

Step 2: Decide If You Actually Need Cross-Domain Tracking

Not every setup needs all the bells and whistles.

Ask yourself: - Do users realistically move between these domains in the same journey? - Am I actually going to use the unified visitor data, or am I just collecting it “because I can”? - Are there privacy or consent considerations if you start linking visitor data across brands?

If your answer to any of these is “not really,” save yourself the trouble. Standard Canddi installs on each domain might be enough.

Step 3: Use the Same Canddi Account and Tracking Code

If you do want unified tracking, you need to use the same Canddi account and tracking code across all your domains.

  • Don’t set up separate Canddi accounts. This splits your data for good.
  • Get your main Canddi script (it’ll look like something you paste into your site footer) and use that exact code on every domain you want to track.

Heads up: If you’re using website builders or CMSs, double-check that the code gets added to every page—not just the homepage.

Step 4: Set Up Cross-Domain Visitor Identification

Here’s where things get technical—and where most tracking setups fall down.

Canddi uses cookies tied to each domain. Browsers won’t let siteA.com read siteB.com’s cookies (for good reason). So, you have to pass the Canddi visitor ID between domains, usually via URL parameters.

How this works in plain English: - When a visitor clicks a link from one tracked domain to another, you append their Canddi visitor ID to the URL (e.g., ?CANDDIVisitor=abc123). - The destination site’s Canddi script reads the parameter, connects the dots, and treats the visitor as the same person.

How to Implement It

  1. Modify your links between domains to include the Canddi visitor ID.

    • Canddi offers helpers or plugins for this, but you can do it manually too.
    • Example:
      If your link is <a href="https://siteB.com/page">Go to Site B</a>,
      you want to turn it into
      <a href="https://siteB.com/page?CANDDIVisitor=abc123">Go to Site B</a>

  2. Use Canddi’s JavaScript helper to automatically append the visitor ID to cross-domain links.
    If you have a lot of links, don’t try to do this by hand. Use the script provided by Canddi, or ask their support for the latest recommended snippet.

  3. On the destination domain, make sure the Canddi script is set to read the CANDDIVisitor parameter on page load and set the cookie accordingly.
    This is usually handled by the default Canddi script, but double-check documentation, as implementation changes over time.

What to ignore:
Don’t waste time trying to hack around browser limitations with iframes or sketchy third-party cookies. Modern browsers block this for privacy reasons.

Step 5: Check Your Consent and Privacy Settings

GDPR, CCPA, and similar laws mean you can’t just pass personal data around like it’s 2012.

  • Make sure your privacy policy covers multi-domain tracking.
  • If you use a consent manager (like Cookiebot or OneTrust), test that Canddi’s cookies and cross-domain tracking don’t fire before consent.
  • Don’t pass personal data in the URL. Only use the Canddi visitor ID, not email addresses or names.

Reality check:
If you’re in a regulated industry, or if your domains target different countries, get legal advice. Not fun, but necessary.

Step 6: Test (and Test Again)

You can set everything up perfectly and still have gaps.

  • Clear your cookies and try a cross-domain journey.
    Open an incognito window, go from Domain A to Domain B via a link, and check that the visitor ID stays the same in Canddi reports.
  • Check for duplicate visitors.
    If you see the same person showing up twice in Canddi, something’s off with your setup.
  • Try direct entry.
    What if someone lands on Domain B from Google, not via a tracked link? Decide if you care about this edge case.

Pro tip:
Don’t just test once and forget. Any time you redesign, change your CMS, or update your consent platform, test again.

Step 7: Keep It Simple—Don’t Overengineer

There’s a temptation to get fancy: tracking every micro-site, campaign domain, and redirect. Resist it.

  • Stick to your main domains.
    The more domains you add, the more likely something breaks.
  • Don’t obsess over edge cases.
    A 99% solution beats a 50% solution that tries to do everything.

What Actually Works (and What Doesn’t)

What Works

  • Using the same Canddi account and script everywhere.
  • Passing the Canddi visitor ID via URL parameters for cross-domain links.
  • Keeping your domain list short and focused.
  • Testing after every change.

What Doesn’t

  • Relying on third-party cookies. (Browsers kill them.)
  • Expecting Canddi to magically unify visitors with no extra setup.
  • Ignoring privacy laws.
  • Manually updating hundreds of links by hand.

TL;DR: Don’t Make It Harder Than It Is

Cross-domain tracking in Canddi isn’t plug-and-play, but it’s totally doable if you know the limitations and set things up right. Use one account, pass the visitor ID in URLs, keep privacy in mind, and test your setup before you trust the data.

Start with the basics. Get it working for your most important domains and user journeys. If it works, then consider expanding. Most tracking headaches come from overcomplicating things—so keep it simple and iterate.