UTMGuard
technical-guidesUpdated 2025

URL Structure and UTM Basics: Complete Beginner's Guide

Learn URL structure fundamentals: paths, query strings, fragments. Master UTM parameter placement for perfect GA4 tracking.

Lily C
•8 min readtechnical-guides

You're building your first marketing campaign. Someone tells you to "add UTM parameters to the URL."

You open a URL builder. You copy-paste some parameters. You launch the campaign.

Then GA4 shows zero campaign data.

What went wrong? You don't understand URL structure. And that's okay—this guide explains everything.

Table of contents

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URL Anatomy 101

Every URL has up to 5 main parts:

Code
https://shop.com:443/products/shoes?utm_source=facebook&size=10#reviews
  ↑       ↑      ↑       ↑              ↑                           ↑
scheme  domain port    path          query string             fragment

1. Scheme: https://
2. Domain: shop.com
3. Port: :443 (usually hidden)
4. Path: /products/shoes
5. Query string: ?utm_source=facebook&size=10
6. Fragment: #reviews

For marketing campaigns, you care about:

  • Path: Where users land
  • Query string: Where UTM parameters go
  • Fragment: Optional anchor link

Part 1: The Scheme (Protocol)

Code
https://shop.com
↑
scheme

Common schemes:

  • https:// - Secure web (recommended)
  • http:// - Insecure web (avoid)
  • mailto: - Email addresses
  • tel: - Phone numbers

For campaigns: Always use https:// (more secure, better SEO).

Part 2: The Domain

Code
https://shop.com/products
       ↑
     domain

Examples:

  • shop.com
  • www.shop.com
  • subdomain.shop.com

For campaigns: Use your primary domain (match your GA4 property).

Part 3: The Path

Code
https://shop.com/products/shoes/nike-air-zoom
                ↑
              path

The path is where users land on your site:

  • / - Homepage
  • /products - Products page
  • /products/shoes - Shoes category
  • /blog/article - Blog post

For campaigns: Point to your landing page path.

Part 4: The Query String (UTM Parameters Go Here)

Code
https://shop.com/products?utm_source=facebook&utm_medium=cpc
                         ↑
                   query string starts with ?

Query String Rules

  1. Starts with ? (question mark)
  2. Parameters separated by & (ampersand)
  3. Format: key=value
  4. Example: ?color=blue&size=10&utm_source=facebook

Query String Anatomy

Code
?utm_source=facebook&utm_medium=cpc&utm_campaign=spring
↑      ↑        ↑    ↑      ↑       ↑      ↑
│      │        │    │      │       │      │
│      │        │    │      │       │      └─ value
│      │        │    │      │       └──────── key
│      │        │    │      └────────────────── separator
│      │        │    └───────────────────────── value
│      │        └────────────────────────────── key
│      └─────────────────────────────────────── separator
└────────────────────────────────────────────── starts query string

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Part 5: The Fragment (Anchor Links)

Code
https://shop.com/products?utm_source=facebook#reviews
                                              ↑
                                          fragment

Purpose: Scroll to specific section on page.

Example HTML:

Html
<div id="reviews">Customer Reviews</div>
 
URL: shop.com/products#reviews → Scrolls to reviews section

Important: Fragment comes AFTER query string.

URL Order Matters

✅ CORRECT Order

Code
https://shop.com/products?utm_source=facebook#reviews
         1       2           3                     4

1. Domain
2. Path
3. Query string (UTMs)
4. Fragment

❌ WRONG Order

Code
https://shop.com/products#reviews?utm_source=facebook
         1       2           4          3

Problem: Fragment comes before query string
Result: UTMs become part of fragment, not sent to server

UTM Parameters Explained

The 5 UTM Parameters

Code
?utm_source=facebook      # Where traffic comes from
&utm_medium=cpc           # Marketing medium (channel)
&utm_campaign=spring2024  # Campaign identifier
&utm_content=carousel-v1  # Ad variant (optional)
&utm_term=running-shoes   # Keyword/audience (optional)

Required vs Optional

Required (always use):

  • utm_source - Traffic source (facebook, google, email)
  • utm_medium - Marketing medium (cpc, social, email, organic)
  • utm_campaign - Campaign name (spring2024, launch, retarget)

Optional (use when needed):

  • utm_content - Ad creative or link variant (banner-v1, text-link)
  • utm_term - Paid search keyword or audience (running-shoes, lookalike)

Parameter Naming Rules

✅ Do:

  • Use lowercase: utm_source=facebook
  • Use hyphens: utm_campaign=spring-sale-2024
  • Use underscores: utm_campaign=spring_sale_2024
  • Keep it short: utm_campaign=spring24

❌ Don't:

  • Use uppercase: utm_source=Facebook (breaks channel grouping)
  • Use spaces: utm_campaign=spring sale (breaks URL)
  • Use special chars: utm_campaign=spring&sale (breaks parsing)

Building Your First Campaign URL

Step 1: Start with Landing Page

Code
https://shop.com/products/shoes

Step 2: Add Question Mark

Code
https://shop.com/products/shoes?
                               ↑
                          Add this

Step 3: Add utm_source

Code
https://shop.com/products/shoes?utm_source=facebook

Step 4: Add utm_medium

Code
https://shop.com/products/shoes?utm_source=facebook&utm_medium=cpc
                                                    ↑
                                            Add & separator

Step 5: Add utm_campaign

Code
https://shop.com/products/shoes?utm_source=facebook&utm_medium=cpc&utm_campaign=spring2024

Step 6: (Optional) Add Fragment

Code
https://shop.com/products/shoes?utm_source=facebook&utm_medium=cpc&utm_campaign=spring2024#featured

Final URL: Complete and valid!

Common URL Structure Mistakes

Mistake 1: No Question Mark

Code
❌ shop.com/products utm_source=facebook
✅ shop.com/products?utm_source=facebook

Mistake 2: Fragment Before Query

Code
❌ shop.com/products#section?utm_source=facebook
✅ shop.com/products?utm_source=facebook#section

Mistake 3: Using & Instead of ?

Code
❌ shop.com/products&utm_source=facebook
✅ shop.com/products?utm_source=facebook

Mistake 4: Multiple Question Marks

Code
❌ shop.com/products?color=blue?utm_source=facebook
✅ shop.com/products?color=blue&utm_source=facebook

Mistake 5: Spaces in Parameters

Code
❌ shop.com/products?utm_campaign=spring sale
✅ shop.com/products?utm_campaign=spring-sale

Testing Your URL

Method 1: Browser Console

Javascript
const url = new URL('YOUR_CAMPAIGN_URL');
console.log('UTM Source:', url.searchParams.get('utm_source'));
console.log('UTM Medium:', url.searchParams.get('utm_medium'));
console.log('UTM Campaign:', url.searchParams.get('utm_campaign'));

Expected: All three should show values, not null.

Method 2: GA4 Real-Time

  1. Visit your campaign URL in incognito mode
  2. Open GA4 → Real-Time reports
  3. Look for your session with campaign attribution
  4. Verify source, medium, campaign appear correctly

Method 3: URL Validator

Paste into a URL validator tool:

  • Check for syntax errors
  • Verify length (< 420 chars for GA4)
  • Confirm all parameters detected

URL Building Best Practices

1. Use a URL Builder

Don't build manually. Use:

  • Google's Campaign URL Builder
  • Your marketing platform's builder
  • UTMGuard's validator
  • Custom team template

2. Follow Naming Conventions

Create a standard format:

Code
utm_campaign format: `{"{"}{"{"}year{"}"}{"}"}}`-`{"{"}{"{"}type{"}"}{"}"}}`-`{"{"}{"{"}detail{"}"}{"}"}}`

Examples:
2024-spring-shoes
2024-launch-prodX
2024-retarget-cart

3. Validate Before Launch

Always check: ✅ URL length < 420 characters ✅ Question mark before first parameter ✅ Fragment (if used) comes last ✅ No spaces or special characters ✅ All parameters lowercase

4. Test in GA4

Never skip testing:

  1. Visit URL in incognito
  2. Check GA4 Real-Time
  3. Verify campaign appears
  4. Confirm all parameters tracked

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FAQ

What's the difference between path and query string?

Path is WHERE users land (/products). Query string is additional DATA sent with the request (?utm_source=x).

Can I have a URL with only a query string and no path?

Yes: shop.com?utm_source=facebook (path defaults to /).

Do query parameters affect SEO?

UTM parameters don't affect SEO. Google strips them when indexing. Use canonical tags to be safe.

Can I use uppercase in UTM parameters?

Technically yes, but DON'T. GA4 channel grouping is case-sensitive. Always use lowercase.

What's the maximum URL length?

Google Search supports 2,048 chars. But GA4 truncates at 420 chars. Always stay under 420.

Can I have spaces in URLs?

Spaces must be URL-encoded as %20. Better practice: use hyphens instead.

Conclusion

URL structure for UTM tracking:

Code
https://domain.com/path?utm_source=x&utm_medium=y&utm_campaign=z#anchor

Order:
1. Domain and path
2. ? (starts query string)
3. UTM parameters (& separators)
4. # (optional anchor)

Master this structure once, and every campaign URL will track perfectly.

Technical Reference: Missing Query Separator Validation Rule

UTM

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