What Are Strange Number Links in Google Analytics?

Ever opened your Google Analytics 4 Landing Page report, ready to see which pages are drawing people in, only to be ambushed by a list of strange, random number strings instead of familiar URLs? It's a frustrating moment that can make you question your entire setup. This article will show you exactly what those number links are, why they appear, and how to fix your reports for good.

What Are Those Strange Number Links in GA4?

If you're seeing landing pages that look like "7854219801.1712345678," you're not alone. While it looks like a server error or a bug, the reality is a bit more mundane. In most cases, these strange numbers are simply how GA4 struggles to display sessions where the landing page value is (not set).

The numbers themselves are often a combination of the Google Analytics Client ID and the session timestamp, concatenated together. Think of it as GA4’s attempt to assign a unique placeholder to a session when it can't find the first page a user landed on. The core issue isn’t the number itself, but the '(not set)' value lurking behind it.

Simply put, '(not set)' appears when GA4 initiates a session but doesn't receive the information it expects. For landing pages, this means it couldn't identify the URL of the very first pageview in that user's session. Getting to the root cause means figuring out why that initial data is going missing.

The Usual Suspects: Why Landing Page Data Goes Missing

There are several common reasons why GA4 might fail to capture the landing page, leading to those confusing number links. By understanding these culprits, you can start building a much cleaner dataset.

1. Inconsistent or Broken UTM Tagging

The most frequent cause stems from how you track your campaigns. Urchin Tracking Module (UTM) parameters are tags you add to your URLs to tell Google Analytics exactly where your traffic is coming from.

• What it is: A URL with UTM tags looks like this: https://yourwebsite.com/landing-page?utm_source=facebook&utm_medium=cpc&utm_campaign=spring_sale
• How it breaks: If a user clicks on a poorly tagged link, GA4 gets confused. For example, if you send an email with a link but forget the utm_source tag, GA4 logs the click but might struggle to tie it to a proper session start. This can result in session data starting without a clear landing page, leading to (not set).

2. Redirect Chains That Strip Parameters

Your marketing links may not always go directly to the final landing page. Sometimes they pass through redirects like a shortening service (e.g., bit.ly) or internal routing rules on your website.

• What it is: A user clicks bit.ly/your-deal, which then redirects to yourwebsite.com/sale?utm_params...
• How it breaks: A poorly configured redirect can "strip" the UTM parameters off the end of your URL. The user still arrives at the right destination, but the tracking data that tells GA4 where they came from is lost in transit. By the time the user lands, GA4 just sees a direct visit with no context, causing a (not set) entry.

3. Session Timeouts and Technical Glitches

In GA4, a session is a group of user interactions within a given timeframe. By default, a session times out after 30 minutes of inactivity.

• What it is: A user opens a blog post on your site, reads for ten minutes, and then walks away from their computer for 45 minutes to take a phone call. When they return, they click on an internal link to another page on your site.
• How it breaks: The original session has timed out. The user's first action in this new session isn't an external click with campaign data, it's an internal-site navigation. GA4 sees this as the very beginning of a new session but has no marketing campaign data to associate with it. Since it wasn't the "first" pageview from an external source, it can sometimes be recorded as (not set).

4. Conflicts Between Google Ads Auto-Tagging and Manual UTMs

If you run Google Ads, you should be using auto-tagging. This feature automatically adds a little piece of code called a GCLID (Google Click Identifier) to your URLs. This provides much richer data than manual UTMs can.

• What it is: Auto-tagging handles all campaign tracking for Google Ads clicks automatically.
• How it breaks: Sometimes, advertisers try to use both auto-tagging and manual UTM parameters for their Google Ads campaigns. This can create conflicts. While GA4 is better at handling this than its predecessor, messy or contradictory tracking can cause data attribution issues, occasionally resulting in (not set) values. The best practice is clear: if auto-tagging is on for Google Ads, let it do its job and don't add manual UTMs for those specific links.

How to Find and Fix the Problem

Now that you know the likely causes, you can take concrete steps to clean up your reports and prevent these strange number links from showing up in the future. Follow this structured approach to diagnose and fix the issue.

Step 1: Perform a UTM Audit

Your first and most important step is to review your current campaign links. Consistency is your best defense against bad data.

• Create a Master Spreadsheet: Make a simple spreadsheet in Google Sheets or Excel to document your campaign tracking URLs. Columns should include: Date, Campaign Name, Channel (e.g., Email, Facebook Ads), URL, utm_source, utm_medium, and utm_campaign.
• Use a URL Builder: Don't try to build tracking links by hand. This leads to typos. Use Google's Campaign URL Builder for GA4 to create standardized, error-free URLs every single time.
• Check Your Live Campaigns: Go through your active ads, social media posts, and recent email newsletters. Find the links you're using and check them against your new spreadsheet. Fix any inconsistencies. Pay close attention to rules, like always using lowercase for source and medium (e.g., facebook is different from Facebook in GA4).

Step 2: Investigate Your Landing Page Report in GA4

With a baseline for what your links should look like, head into GA4 to see what's actually being reported. Go beyond the default view to uncover clues.

1. Navigate to Reports > Engagement > Landing page.
2. You'll likely see the problematic number links here. To see the underlying (not set) value, you might need to try different reporting views.
3. Click the "+" button next to Landing page + query string on the table to add a secondary dimension. Search for and add Session source / medium.

Now, look at the rows with the strange number links. What does the Session source / medium column say for them? If it's (direct) / (none) or shows an unexpected source, it's a strong clue that campaign parameters from another source are being lost before the session is recorded.

Step 3: Test All Redirects

Do you use a link-shortening service or have vanity URLs that redirect to your actual pages? It's time to test them one by one.

1. Take one of your freshly built UTM links from the URL builder.
2. Paste it into its redirect tool (like Bitly or your website's redirect manager).
3. Take the new, shortened link. Open a new Incognito browser window (this prevents your own cookies from interfering).
4. Paste the shortened link and hit Enter. Watch the address bar closely as the page loads.
5. Once the final page loads, check the address bar again. Are all the utm_ parameters still there? If they've vanished, you've found your culprit. Contact your web developer or check the settings in your redirect tool to ensure it passes through all URL parameters.

Step 4: Create a Clean Report by Filtering Out Bad Data

While you work on fixing the root causes, you still need to pull clean reports. You can create a temporary fix by building a custom Exploration report that filters out the junk data.

1. Go to the Explore section in GA4 and start a new "Free Form" exploration.
2. In the Variables column, click the "+" next to Dimensions and import Landing page, Session source / medium, and Host.
3. Click the "+" next to Metrics and import Sessions and Engaged sessions.
4. Drag Landing page onto the "Rows" area in the main panel.
5. Drag Sessions and other metrics onto the "Values" area.
6. At the bottom of the Variables panel, you'll see a section called Filters. Drag Landing page into the filter box.
7. Set the filter to: does not contain and enter (not set).
8. You might also add a filter for Host exactly matches your website domain (e.g., yourwebsite.com) to filter out any potential spam traffic.

This filtered report will give you a clean view of your data while you work on implementing the technical fixes on your website and in your campaigns.

Final Thoughts

Seeing strange number strings in your Google Analytics reports is jarring, but it's almost always a fixable data quality problem. These numbers are typically side effects of (not set) landing page values, which point to issues in your campaign tagging, site redirects, or session settings. By methodically auditing your links and testing your setup, you can clean up your data and regain confidence in your analytics.

We know that manually hunting for (not set) values and building URL spreadsheets is exactly the kind of tedious reporting work that gets in the way of actual marketing. That's why we built Graphed. Instead of wrestling with GA4's interface, you can simply connect your data and ask "Show me my top performing landing pages from Facebook this month," and instantly get a clean, real-time report. Our AI-powered analytics handle the complexity so you can spend less time cleaning data and more time acting on it.