GA4 420 Character Limit Fix: Stop URL Truncation

Your campaign URLs are getting truncated in GA4. Campaign names cut off mid-word. UTM parameters disappearing.

The cause: You're exceeding GA4's 420-character URL limit.

The fix: 5 minutes to shorten your URLs and restore full tracking.

The 420-Character Rule

Google Analytics 4 truncates URLs at exactly 420 characters.

Character 1-420:   ✅ Tracked
Character 421+:    ❌ Discarded

No warning. No error. Just silently cuts off your data.

Quick Diagnosis (30 Seconds)

Test Your Campaign URL

// Paste in browser console:
'YOUR_CAMPAIGN_URL_HERE'.length
 
// Example:
'https://shop.com/products/category?utm_source=facebook&utm_medium=cpc&utm_campaign=super-long-campaign-name-2024-Q1-spring-sale-womens-shoes-category-special-promotion'.length
// Returns: 472
 
// If result > 420: You have the problem

Visual Test

Paste your URL into GA4 → Real-Time reports. If the campaign name looks truncated or incomplete, you're over the limit.

The 5-Minute Fix

Step 1: Identify the Longest Parts (1 minute)

Break down your URL:

https://                                    8 chars
very-long-domain-name.com                  25 chars
/very/long/path/to/page                    23 chars
?utm_source=facebook-advertising            29 chars
&utm_medium=paid-social-cpc                 27 chars
&utm_campaign=2024-Q1-long-campaign-name   42 chars
&utm_content=ad-variant-description         35 chars
&utm_term=keyword-phrase                    24 chars
────────────────────────────────────────────────
TOTAL:                                     213 chars

Find the longest components. Those are your optimization targets.

Step 2: Shorten Campaign Name (2 minutes)

❌ BEFORE (82 chars):
utm_campaign=2024-Q1-spring-sale-womens-running-shoes-category-free-shipping-promo

✅ AFTER (32 chars):
utm_campaign=2024-Q1-spring-womens

Shortening strategies:

• Remove redundant words (category, promo, sale)
• Use abbreviations (Q1 instead of quarter-1)
• Drop year if not needed for reporting
• Use codes instead of descriptions

Step 3: Abbreviate UTM Parameters (1 minute)

❌ BEFORE:
utm_source=facebook-advertising-platform
utm_medium=paid-social-media-cpc
utm_content=carousel-advertisement-blue-version

✅ AFTER:
utm_source=facebook
utm_medium=paidsocial
utm_content=carousel-blue

Common abbreviations:

• facebook → fb (or keep facebook)
• paid-social → paidsocial
• cost-per-click → cpc
• advertisement → ad
• version → v

Step 4: Shorten URL Path (30 seconds)

❌ BEFORE:
https://online-store.com/products/category/subcategory/item-name

✅ AFTER:
https://online-store.com/p/item-name

Step 5: Validate (30 seconds)

// Check new length
'YOUR_NEW_URL_HERE'.length
 
// Must be ≤ 420

Test in GA4 Real-Time to confirm campaign appears complete.

Real Example: 487 → 398 Characters

Before (487 chars):

https://fashion-outlet-store.com/products/womens/shoes/running/brands/nike?utm_source=facebook-advertising-platform&utm_medium=paid-social-media-cost-per-click&utm_campaign=2024-spring-sale-womens-running-shoes-nike-brand-discount&utm_content=carousel-ad-blue-background-version-A&utm_term=womens-nike-running-shoes

After (398 chars):

https://fashionoutlet.com/p/nike-running?utm_source=facebook&utm_medium=paidsocial&utm_campaign=2024-spring-womens-nike&utm_content=carousel-blue-a&utm_term=nike-running

Changes made:

1. Shortened domain: fashion-outlet-store.com → fashionoutlet.com
2. Shortened path: /products/womens/shoes/running/brands/nike → /p/nike-running
3. Shortened source: facebook-advertising-platform → facebook
4. Shortened medium: paid-social-media-cost-per-click → paidsocial
5. Shortened campaign: removed redundant words
6. Shortened content: carousel-ad-blue-background-version-A → carousel-blue-a
7. Shortened term: womens-nike-running-shoes → nike-running

Result: 89 characters saved, full tracking restored.

URL Length Budget Calculator

Use this formula to stay under 420 chars:

Protocol:              8 chars (https://)
Domain:              ≤ 20 chars
Path:                ≤ 30 chars
utm_source:          ≤ 20 chars
utm_medium:          ≤ 15 chars
utm_campaign:        ≤ 30 chars
utm_content:         ≤ 20 chars (optional)
utm_term:            ≤ 20 chars (optional)
Separators:            7 chars (?&&&&&)
───────────────────────────────
TOTAL:               170 chars

BUFFER:              250 chars (for longer values)
───────────────────────────────
MAX:                 420 chars

Alternative: URL Shorteners

If shortening isn't enough, use URL shorteners:

❌ Long (487 chars):
https://very-long-domain.com/very/long/path?utm_source=...

✅ Shortened (72 chars):
https://bit.ly/abc123?utm_source=facebook&utm_campaign=spring2024

Best practices:

• Keep UTM parameters on the SHORT URL
• Test that shortener preserves parameters
• Use branded shorteners (brand.link) when possible

FAQ

Can I increase GA4's 420-char limit?

No. It's a hard limit in GA4 and cannot be changed.

What if I need long campaign names for reporting?

Use short campaign names in UTMs, then create custom dimensions in GA4 to map to longer descriptions.

Do URL shorteners affect tracking?

No, as long as you add UTM parameters to the SHORT URL, not the original long URL.

What gets truncated first?

GA4 truncates from right to left (end of URL first), so utm_term and utm_content are usually lost first.

Will fixing this affect historical data?

No. Historical data is already truncated and can't be recovered. The fix only applies to future tracking.

Should I shorten ALL my campaign URLs?

Yes. Even if you're under 420 chars now, it's good practice to keep URLs short for better user experience and future-proofing.

Conclusion

GA4 truncates URLs over 420 characters, breaking campaign tracking.

Quick fix:

1. Check URL length (must be ≤ 420)
2. Shorten campaign names
3. Abbreviate UTM parameters
4. Shorten domain/path if needed
5. Validate length and test

Takes 5 minutes. Saves your campaign attribution forever.

Technical Reference: URL Length Exceeded Validation Rule