What This Rule Detects

Detects URLs containing more than one question mark (?) character. URLs can only have ONE ? to separate the path from query parameters. Additional ? characters corrupt parameter parsing, causing everything after the second ? to become part of the previous parameter's value instead of being parsed as separate parameters.

Why It Matters

Business Impact:

• Unpredictable tracking behavior - Parameters parsed incorrectly
• Data corruption - Parameter values include unintended text
• Fragmented reporting - Same campaign appears in multiple broken forms
• Broken links - Some platforms reject URLs with multiple ?
• Attribution errors - UTM values contaminated with subsequent parameters

Technical Impact:

• The ? character has special meaning: It marks the start of the query string
• When multiple ? exist, only the FIRST one is treated as query separator
• Everything after the second ? becomes the VALUE of the previous parameter
• Parameter parsing stops at second ?, losing subsequent parameters entirely
• Creates malformed parameter values that don't match campaign names

Real Example:

• Intended URL: example.com?page=1&utm_source=google&utm_medium=cpc
• Malformed URL: example.com?page=1?utm_source=google&utm_medium=cpc
• What GA4 receives:
  • page = "1?utm_source=google&utm_medium=cpc" (wrong!)
  • utm_source = (not set) (lost!)
  • utm_medium = (not set) (lost!)
• Result: Direct traffic, 100% tracking failure

Common Scenarios

Scenario 1: Double Query String Concatenation

Combining two URLs with existing query parameters:

Scenario 2: Encoded URL as Parameter Value

Passing a full URL as a parameter without proper encoding:

Scenario 3: Copy-Paste Error from Multiple Sources

Accidentally duplicating the ? when building URLs manually:

How to Fix

Step 1: Understand URL Query String Syntax

URL structure rule:

https://example.com/path?param1=value1&param2=value2&param3=value3
                        │            │          │
                        │            │          └─ Third parameter (use &)
                        │            └─ Second parameter (use &)
                        └─ First parameter (use ?)

ONE question mark, MULTIPLE ampersands

Critical rules:

• ✅ Use ? ONCE to start query string
• ✅ Use & to separate ALL additional parameters
• ❌ Never use ? between parameters
• ❌ Never use multiple ? characters

Step 2: Identify Multiple Question Marks

Check your URL:

1. Count the ? characters in your URL
2. There should be EXACTLY ONE
3. If you find 2 or more, you have this error

Detection pattern:

❌ example.com?page=1?utm_source=google (2 question marks)
❌ example.com?id=123?source=fb?medium=cpc (3 question marks!)
✅ example.com?page=1&utm_source=google (1 question mark, correct)

Step 3: Fix the URL Structure

Simple fix - Replace extra ? with &:

Example 1:

❌ Before: example.com?page=1?utm_source=google&utm_medium=cpc
✅ After:  example.com?page=1&utm_source=google&utm_medium=cpc
                           Replace ? with & ─^

Example 2:

❌ Before: shop.com?category=shoes?color=blue?utm_source=facebook
✅ After:  shop.com?category=shoes&color=blue&utm_source=facebook
                                  ^         ^
                           Replace both ? with &

Example 3 (URL as parameter - requires encoding):

❌ Before: example.com?redirect=https://other.com?id=123&utm_source=email
✅ After:  example.com?redirect=https://other.com%3Fid%3D123&utm_source=email
                                                  ^  ^
                           Encode ? as %3F and = as %3D in parameter values

Step 4: Handle URLs Within Parameter Values

Special case: If you're passing a URL as a parameter value, you MUST URL-encode it:

Wrong approach:

❌ example.com?next=https://destination.com?param=value&utm_source=google
   Problem: Second ? breaks parsing

Correct approach:

✅ example.com?next=https%3A%2F%2Fdestination.com%3Fparam%3Dvalue&utm_source=google

Encoding:
- : → %3A
- / → %2F
- ? → %3F
- = → %3D

Use URL encoding tools:

• JavaScript: encodeURIComponent("https://destination.com?param=value")
• Python: urllib.parse.quote("https://destination.com?param=value")
• Online: urlencoder.org

Step 5: Update All Campaign URLs

Where to fix:

1. Social media ads: Facebook, LinkedIn, Twitter ad platforms
2. Email campaigns: ESP link builder (Mailchimp, SendGrid, etc.)
3. Display ads: Google Display Network, programmatic platforms
4. Affiliate links: Partner URL templates
5. QR codes: Regenerate with corrected URLs
6. Spreadsheets: Update any URL databases or tracking sheets

Verification:

1. Find/replace all URLs with multiple ?
2. Replace second and subsequent ? with &
3. Test 5-10 sample URLs
4. Click test URLs and verify GA4 Real-Time shows correct attribution
5. Deploy corrected URLs across all platforms

Examples

❌ Incorrect Examples

https://example.com?page=1?utm_source=google&utm_medium=cpc
Parsed as:
- page = "1?utm_source=google&utm_medium=cpc" (WRONG)
- No other parameters recognized
Result: GA4 receives no UTM data, appears as Direct traffic

https://shop.com/products?id=123?category=shoes?utm_source=facebook
Parsed as:
- id = "123?category=shoes?utm_source=facebook" (WRONG)
Result: Complete parameter corruption, 100% tracking failure

https://example.com?redirect=https://other.com?next=page&utm_source=email
Parsed as:
- redirect = "https://other.com?next=page" (breaks after second ?)
- utm_source parameter lost
Result: Tracking fails, redirect may break

✅ Correct Examples

https://example.com?page=1&utm_source=google&utm_medium=cpc
Parsed as:
- page = "1"
- utm_source = "google"
- utm_medium = "cpc"
Tracking: SUCCESS (all parameters captured correctly)

https://shop.com/products?id=123&category=shoes&utm_source=facebook
Parsed as:
- id = "123"
- category = "shoes"
- utm_source = "facebook"
Tracking: SUCCESS (proper parameter separation)

https://example.com?redirect=https%3A%2F%2Fother.com%3Fnext%3Dpage&utm_source=email
Parsed as:
- redirect = "https://other.com?next=page" (decoded correctly)
- utm_source = "email"
Tracking: SUCCESS (URL encoding preserves both parameters and nested URL)

GA4 Impact Analysis

Parameter Parsing:

• Only the first ? is recognized as query separator
• Everything after second ? becomes part of previous parameter's value
• Subsequent parameters are completely lost
• Results in malformed parameter values

Session Attribution:

• UTM parameters after second ? are not extracted
• Traffic appears as Direct / (none)
• Campaign names corrupted or missing
• Source/medium values lost entirely

Channel Grouping:

• Traffic misclassified as Direct channel
• Paid campaigns show zero sessions
• Email/social campaigns invisible in reports
• Channel analysis completely broken

Data Fragmentation:

• Same campaign appears in multiple corrupted forms:
  • "google?utm_medium=cpc"
  • "facebook?utm_medium=social"
  • Each malformed value creates separate entry
• Reports show dozens of broken parameter variants
• Makes campaign consolidation impossible

Reporting Impact:

• Campaign reports: Show incomplete or malformed campaign names
• Source/Medium reports: Missing or corrupted values
• Conversion attribution: Lost for affected traffic
• ROI calculation: Impossible with corrupted campaign data

Detection in UTMGuard

UTMGuard automatically detects multiple question marks:

1. Scans all page URLs in your GA4 data
2. Counts question mark characters in each URL
3. Flags any URL with 2 or more ? characters
4. Reports affected session count
5. Shows malformed parameter values
6. Suggests corrected format with & separators

Audit Report Shows:

• Total sessions with multiple ? characters
• List of malformed URLs
• Corrupted parameter values
• Corrected URL format
• Session count per broken URL pattern

Related Validation Rules

Frequently Asked Questions

Q: How do I know if my URL has multiple question marks?

A: Manually count the ? characters in your URL. Or paste the URL into your browser and check the address bar - browsers often show warnings. Or use UTMGuard to scan all your URLs automatically.

Q: What if I need to pass a URL as a parameter?

A: You must URL-encode the nested URL. Use encodeURIComponent() in JavaScript or online encoding tools. The ? in the nested URL becomes %3F.

Q: Will browsers automatically fix this?

A: No. Browsers strictly follow the rule: first ? starts query string, everything after second ? is treated as text. No automatic correction happens.

Q: Can this cause 404 errors?

A: Not typically, but the page may not load correctly if it expects specific parameter values and receives corrupted data instead.

Q: Does this affect all analytics platforms?

A: Yes. This is a fundamental URL syntax issue. All web servers, browsers, and analytics tools follow the same query string parsing rules.

Q: How do I fix this in bulk across hundreds of URLs?

A: Export your campaign URLs to a spreadsheet, use find/replace to change all instances of ?param= to &param= (except the first ?), then update all platforms with corrected URLs.

Q: What's the difference between ? and &?

A: ? marks the START of the query string (use once). & separates parameters within the query string (use multiple times). Think of ? as "query string begins here" and & as "and here's another parameter".

Q: Can I use # instead of additional ??

A: No! The # character is for URL fragments (anchor links) and comes AFTER query parameters. Correct order: path?query#fragment. Never use # to separate parameters.

External Resources

• RFC 3986: URL Query String Syntax
• W3C URL Standard
• Google Campaign URL Builder
• MDN Web Docs: URL Structure

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