Fix URLs with Uppercase Characters in GA4

The Case File

Your GA4 property is tracking URLs like /Products/Shoes and /products/shoes as separate pages. Same content. Different analytics entries. The result? Your traffic data is fragmented across what should be identical page paths, making it impossible to accurately measure page performance, user behavior, or content effectiveness.

The specific problem: GA4 records the page_location parameter exactly as it appears in the browser—including uppercase characters in paths (/About-Us) and query parameters (?UTM_Source=Facebook). When users access the same page via different URL casings, your reports split the data. What looks like 500 visits to one page might actually be 320 visits to /contact and 180 to /Contact.

This isn't a critical tracking failure. Your data is still being collected. But it's being collected incorrectly, creating a silent accuracy problem that compounds over time.

The Root Causes

1. Server and CMS Configuration

Most modern web servers treat URLs as case-sensitive by default on Linux/Unix systems. Apache and Nginx will serve /Products and /products as distinct resources unless explicitly configured otherwise. Your CMS (WordPress, Shopify, custom builds) may generate links with inconsistent casing:

• Internal navigation links use /Products

• Sitemap URLs use /products

• Manually created links use /PRODUCTS

The GA4 consequence: Each variant creates a separate row in your Pages and Screens report.

2. Marketing Campaign Inconsistency

Your marketing team launches campaigns with UTM parameters. Different team members use different conventions:

• Email team: ?utm_source=newsletter&utm_medium=email

• Social team: ?UTM_Source=Facebook&UTM_Medium=Social

• Paid team: ?Utm_Source=google&Utm_Medium=cpc

GA4 treats utm_source and UTM_Source as different parameters. Your Traffic Acquisition report now shows "newsletter," "Facebook," and "google" as separate sources when they should be aggregated by lowercase convention.

3. User-Generated and External Links

Users share links with modified casing. A blogger links to your /resources page but types /Resources. Social media platforms sometimes auto-capitalize. Browser autocomplete can preserve historical uppercase entries. Each variation reaches your GA4 property as-is.

4. GTM Data Layer Inconsistency

If you're pushing custom page paths to the data layer, developer inconsistency creates the problem at the source:

javascriptCopy code

// Developer A

dataLayer.push({'pagePath': '/Product-Details'});

// Developer B  

dataLayer.push({'pagePath': '/product-details'});

Open in CodePen

Your GA4 configuration event receives mixed casing before the pageview even fires.

5. Redirect Chain Failures

Your site may have redirects that don't normalize casing. A user lands on /ABOUT → your server redirects to /about → but GA4 fires on the initial uppercase URL before the redirect completes. Both URLs appear in your data.

The "So What?" (Business Impact)

This isn't just a cosmetic reporting issue. URL casing fragmentation creates measurable business problems:

Analytics Accuracy: Your top landing page might show 1,000 visits, but the real number is 1,450 when you account for /landing-page, /Landing-Page, and /LANDING-PAGE. Your content performance analysis is built on incomplete data.

Conversion Attribution: If users land on /Products but convert on /products, your funnel visualization breaks. The path appears discontinuous. Your conversion rate calculations by landing page become unreliable.

SEO Coordination: Your SEO team optimizes /products/shoes based on GA4 data showing 500 visits. But Google Search Console reports 800 clicks to that URL. The discrepancy? GA4 is splitting traffic across uppercase variants that GSC normalizes.

Audience Building: You create an audience of users who visited /premium-features to retarget them. But 30% of that traffic hit /Premium-Features and isn't included. Your audience size is artificially deflated.

Executive Reporting: Your monthly report shows traffic to your pricing page declined 15%. Actually, users shifted from /pricing to /Pricing after a marketing email used the wrong casing. The traffic didn't drop—your measurement fragmented.

The Investigation

Without Watson, here's how to detect this issue manually:

1. Navigate to Reports > Engagement > Pages and screens in your GA4 property

2. Set the date range to the last 30 days

3. Export the full page path list (you may need to increase row display to maximum)

4. In a spreadsheet, create a new column with =LOWER(A2) to normalize all URLs

5. Use a pivot table or COUNTIF to identify lowercase URLs that appear multiple times in the original list

6. Sort by views to find high-traffic pages with casing variants

The manual process takes 15-30 minutes per property and must be repeated regularly.

You can also check Explore > Free Form and add:

• Dimension: Page location

• Metric: Views

• Filter: Custom regex on page location containing [A-Z] (requires regex knowledge)

The Solution

Fix 1: Implement Server-Side URL Normalization

For Apache (.htaccess):

apacheCopy code

RewriteEngine On

RewriteMap lowercase int:tolower

RewriteCond %{REQUEST_URI} [A-Z]

RewriteRule ^(.*)$ ${lowercase:$1} [R=301,L]

For Nginx:

nginxCopy code

if ($request_uri ~ [A-Z]) {

    return 301 $scheme://$host$lowercase_uri;

}

This redirects any uppercase URL to its lowercase equivalent before GA4 tracking fires.

Fix 2: Normalize in GTM (Data Layer Override)

Create a Custom JavaScript Variable in GTM named JS - Normalized Page Path:

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function() {

  return {{Page Path}}.toLowerCase();

}

Open in CodePen

Then modify your GA4 Configuration Tag:

• Go to Fields to Set

• Add field name: page_location

• Value: {{Page Protocol}}://{{Page Hostname}}{{JS - Normalized Page Path}}

This forces all page paths to lowercase before sending to GA4.

Fix 3: UTM Parameter Standardization

Create a marketing campaign URL builder policy:

• All UTM parameters must be lowercase

• Use a centralized tool (Google's Campaign URL Builder, or a custom internal form)

• Implement a GTM variable that lowercases UTM parameters on collection:

Variable Name: JS - Normalized UTMs

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function() {

  var url = {{Page URL}};

  return url.replace(/([?&])(utm_[^=]+)=([^&]+)/gi, function(match, p1, p2, p3) {

    return p1 + p2.toLowerCase() + '=' + p3.toLowerCase();

  });

}

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Fix 4: GA4 Data Filters (Limited Solution)

GA4 doesn't offer built-in case normalization filters like Universal Analytics did. You cannot retroactively fix historical data. The solutions above prevent future fragmentation but don't merge existing split data.

For reporting workarounds:

• Use Explorations with calculated fields that apply LOWER() functions

• Export to BigQuery and normalize in SQL queries:

sqlCopy code

SELECT 

  LOWER(page_location) as normalized_page,

  SUM(event_count) as total_events

FROM `project.dataset.events_*`

GROUP BY normalized_page

Fix 5: Content Management System Rules

WordPress: Use a plugin like "Permalink Manager" or "Redirection" to enforce lowercase URLs.

Shopify: Navigate to Online Store > Preferences and ensure "Automatically redirect to the page's URL" is enabled (handles some casing issues).

Custom CMS: Implement URL generation functions that always output lowercase paths.

Case Closed

Finding URL casing inconsistencies manually requires exporting data, spreadsheet analysis, and regex pattern matching—a 20-minute investigation per property that most teams skip until reporting discrepancies become obvious.

The Watson Analytics Detective dashboard identifies this Info-level issue instantly in its URL Quality section, showing you exactly which pages have uppercase variants, their traffic volume, and the percentage of your total URLs affected. Watson scans this check alongside 60+ other data quality validations, from critical PII exposure to subtle attribution breaks.

Stop investigating data quality issues one symptom at a time. Let Watson run the full audit automatically →