Pinterest epik Parameter Explained (Complete Technical Guide)

When someone clicks your Pinterest Ad, Pinterest automatically appends a mysterious epik parameter to your landing page URL. What is it, why does it appear, and should you remove it?

Short answer: The epik parameter is Pinterest's proprietary attribution system—similar to Google's gclid and Facebook's fbclid. It provides more accurate tracking than manual UTM parameters and should never be removed or combined with manual UTMs.

Here's everything you need to know about Pinterest's epik parameter and how it affects your campaign tracking.

What is the epik Parameter?

epik = Pinterest's Enhanced Performance Identification Key (unofficial backronym—Pinterest doesn't officially define the acronym)

It's an automatically-generated parameter that Pinterest appends to all Pinterest Ads clicks, similar to platform click IDs used by other advertising platforms:

Example URL with epik

Before click (your Pinterest Ad):

https://yoursite.com/product

After click (what user sees):

https://yoursite.com/product?epik=dj0yJnU9S2RLNnBkejNhRFpubGVDS1RZZFB3bjhfSGNtQmcmcD0wJm49NHpCVmRqT0E4UzRNVEoyNkZOSnZBUSZ0PUFBQUFBR1pGLVlB

Pinterest automatically injects this parameter—you don't configure it or build it into your URLs.

What Data Does epik Capture?

Unlike manual UTM parameters which only contain the text you specify, epik encodes rich attribution metadata:

Campaign Information

• Campaign ID: Unique identifier for your Pinterest campaign
• Ad Group ID: Which ad group within the campaign
• Pin ID: The specific Pin creative that was clicked
• Campaign objective: Awareness, Consideration, or Conversion

Audience Targeting Data

• Interests targeted: Which interest categories the user matched
• Demographics: Age range, gender (if targeted)
• Keywords: Search keywords that triggered the Pin (for keyword-targeted campaigns)
• Audience list: Whether user was from a custom audience or lookalike

Technical Metadata

• Device type: Desktop, mobile, tablet
• Operating system: iOS, Android, Windows, macOS
• Browser: Chrome, Safari, Firefox, etc.
• Click timestamp: Precise time of ad click
• Attribution window: Conversion window settings (1-day click, 7-day click, 1-day view)

Conversion Tracking

• Pinterest Tag integration: Links click to Pinterest Tag events on your site
• Conversion API match: Connects server-side conversions back to this click
• ROAS calculation: Enables revenue attribution for each Pin

This is data you CANNOT capture with manual UTM parameters.

How epik Works: Technical Flow

Step 1: User Sees Pinterest Ad

You create a Pinterest Ads campaign targeting specific interests, demographics, or keywords. Your destination URL is clean:

https://yoursite.com/shop/blue-dress

Step 2: User Clicks Ad

When clicked, Pinterest's ad server:

1. Generates unique epik value containing all tracking metadata
2. Appends it to your destination URL
3. Redirects user to: yoursite.com/shop/blue-dress?epik=abc123xyz...

Step 3: Pinterest Tag Fires on Your Site

Your website has the Pinterest Tag installed. When the page loads:

1. Pinterest Tag reads the epik parameter from the URL
2. Associates the visit with the Pinterest Ad campaign
3. Begins tracking user actions (page views, add to cart, purchases)

Step 4: Conversion Tracking

When the user converts (purchases, signs up, etc.):

1. Pinterest Tag sends conversion event to Pinterest
2. Event includes the original epik value
3. Pinterest matches conversion back to specific campaign, ad group, and Pin
4. Attribution data flows into Pinterest Ads Manager

Step 5: GA4 Recognition

Google Analytics 4 also recognizes epik:

• Source: pinterest
• Medium: paidsocial (or cpc in some GA4 configurations)
• Default Channel: Paid Social

The session is properly attributed without manual UTM parameters.

epik vs. Manual UTMs: Detailed Comparison

Verdict: epik provides superior attribution with zero configuration.

Why You Should Use epik Instead of Manual UTMs

1. Automatic Pin Performance Tracking

With epik, Pinterest Ads Manager shows performance by individual Pin:

• Pin A (product photo): 5% conversion rate
• Pin B (lifestyle photo): 8% conversion rate
• Pin C (video): 3% conversion rate

Action: Increase budget for Pin B, pause Pin C.

With manual UTMs: You'd need to manually add different utm_content values to each Pin's URL—error-prone and time-consuming.

2. Interest & Keyword Performance

With epik, Pinterest shows which targeted interests convert:

• Interest: "Home Decor" → 12% conversion rate
• Interest: "Interior Design" → 6% conversion rate
• Keyword: "modern furniture" → 9% conversion rate

With manual UTMs: This data is completely unavailable.

3. Cross-Device Attribution

Scenario: User sees Pinterest Ad on mobile, saves Pin, later buys on desktop.

With epik: Pinterest's logged-in data connects both sessions → conversion attributed to original ad.

With manual UTMs: Cookie-based tracking fails → conversion shows as "Direct" traffic in GA4.

4. Zero Manual Work

Manual UTMs require:

https://yoursite.com/product?utm_source=pinterest&utm_medium=cpc&utm_campaign=spring-sale&utm_content=pin-video-1

Issues:

• Build URL for every Pin
• Ensure consistency across team
• Fix typos and errors
• Update for each campaign

epik requires:

https://yoursite.com/product

Pinterest handles everything automatically.

How GA4 Processes epik

GA4 automatically recognizes Pinterest's epik parameter and assigns traffic correctly.

Channel Assignment

When GA4 sees a URL with epik:

https://yoursite.com/product?epik=abc123xyz

GA4 extracts:

• Source: pinterest (identified from epik pattern)
• Medium: paidsocial (GA4's recognized value for Pinterest ads)
• Default Channel: Paid Social

No manual UTMs needed—GA4 handles attribution automatically.

Viewing Pinterest Traffic in GA4

Standard Report:

1. GA4 → Reports → Acquisition → Traffic acquisition
2. Filter: Session source = pinterest
3. See:
   • Source / Medium: pinterest / paidsocial
   • Sessions, conversions, revenue

Custom Analysis: Create custom dimension to capture epik values for detailed analysis:

1. GA4 → Admin → Custom definitions → Create custom dimension
2. Dimension name: Pinterest epik
3. Scope: Event
4. Event parameter: epik

Common Issues & Troubleshooting

Issue 1: epik + Manual UTMs = Duplicate Sessions

Problem: You added manual UTMs to Pinterest Ads, but Pinterest still appends epik.

Result: GA4 creates two sessions:

• Session 1: pinterest / cpc (from your UTMs)
• Session 2: pinterest / paidsocial (from epik)

Impact: 100% session inflation, fragmented conversion data.

Fix: Remove manual UTMs. Let epik handle attribution alone.

See detailed guide: Fix Pinterest UTM Conflict

Issue 2: epik Parameter Stripped by Redirect

Problem: Your Pinterest Ad URL redirects (301, 302) before reaching final destination. The redirect strips the epik parameter.

Symptoms:

• Pinterest Ad clicks show as "Direct" in GA4
• Pinterest Ads Manager shows zero conversions despite sales

Fix:

• Use direct landing pages (no redirects)
• If redirect is required, ensure it preserves query parameters
• Test: Click test ad, verify epik appears in final URL

Issue 3: No Conversion Data in Pinterest Ads Manager

Problem: GA4 shows conversions from Pinterest traffic, but Pinterest Ads Manager shows zero.

Cause: Pinterest Tag not installed or conversion events not configured.

Fix:

1. Install Pinterest Tag on your website
2. Set up conversion events in Pinterest Ads Manager
3. Match events between GA4 and Pinterest (e.g., "purchase")

See: Pinterest Tag Installation Guide

Platform Comparison: epik vs. Other Click IDs

Pattern: Major ad platforms use auto-tagging. Manual UTMs are unnecessary and create conflicts.

See comprehensive guide: Platform Click ID vs. Manual UTMs

FAQ

What does epik stand for?

Pinterest hasn't officially defined the acronym. Industry consensus is Enhanced Performance Identification Key, but this is unofficial. The actual meaning is less important than understanding its function as Pinterest's attribution parameter.

Can I decode the epik parameter to see what data it contains?

No. epik is an encrypted identifier. Only Pinterest's servers can decrypt it. However, all the data captured by epik is available in Pinterest Ads Manager's campaign performance reports.

Does epik work for organic Pinterest traffic?

No. epik only appears on Pinterest Ads clicks. Organic Pinterest traffic (Pins shared by users, not ads) appears as "pinterest / referral" in GA4 without epik.

Should I use both epik and manual UTMs?

No. Using both creates duplicate sessions in GA4 and fragments conversion data. Choose one:

• Recommended: epik only (automatic, more data, zero errors)
• Not recommended: Manual UTMs (manual work, less data, error-prone)

99% of Pinterest advertisers should use epik only.

How long is the epik parameter value?

Typically 80-120 characters. The exact length varies based on how much metadata is encoded.

Example:

?epik=dj0yJnU9S2RLNnBkejNhRFpubGVDS1RZZFB3bjhfSGNtQmcmcD0wJm49NHpCVmRqT0E4UzRNVEoyNkZOSnZBUSZ0PUFBQUFBR1pGLVlB

This is normal and doesn't impact page load speed or SEO.

Can I shorten URLs with epik using Bitly or similar?

Yes, but test carefully. Some link shorteners may strip query parameters including epik. Always verify:

1. Shorten URL with epik
2. Click shortened link
3. Verify epik appears in final destination URL

Most modern shorteners (Bitly, TinyURL) preserve epik correctly.

Does epik affect SEO?

No. epik is a query parameter and doesn't affect SEO. Google treats URLs with different query parameters as the same page for indexing purposes (assuming proper canonical tags).

Can I track specific Pinterest campaigns without epik?

No. If you disable auto-tagging or remove epik, Pinterest can't track conversions back to specific campaigns. You'd lose all campaign-level performance data in Pinterest Ads Manager.

Bottom line: epik is required for Pinterest Ads attribution.

Why does epik show as "paidsocial" instead of "cpc" in GA4?

GA4's default channel grouping assigns Pinterest traffic with epik to the "Paid Social" channel with medium "paidsocial". This is correct—Pinterest is a social platform, not a search engine.

If you prefer different naming, create a custom channel grouping in GA4.

What happens if a user bookmarks a page with epik in the URL?

If a user bookmarks yoursite.com/product?epik=abc123xyz and returns later via bookmark, GA4 sees it as a new direct session (since the referrer is the bookmark, not Pinterest).

However, the original Pinterest ad click was already tracked with epik, so attribution is correct. The return visit is legitimately "Direct".

Related Resources

Internal Guides

• Fix Pinterest UTM Conflict - Resolve duplicate sessions from epik + UTMs
• Pinterest Attribution Best Practices - Advanced Pinterest measurement
• Pinterest Ads Tracking Issues - Common problems and solutions
• Platform Click ID Conflicts - Auto-tagging across all platforms

Pinterest Official Documentation

• Pinterest Tag Installation
• Pinterest Conversion Tracking
• Pinterest Ads Manager Help

External Resources

• Google Analytics Default Channel Grouping - How GA4 handles epik

Conclusion

Pinterest's epik parameter is the automatic, superior alternative to manual UTM parameters for Pinterest Ads.

Unlike manual UTMs, epik provides:

• ✅ Zero configuration (automatic)
• ✅ Pin-level performance tracking
• ✅ Audience interest and keyword data
• ✅ Cross-device attribution
• ✅ Seamless Pinterest Tag and Conversion API integration
• ✅ Zero human errors

Best practice for Pinterest Ads:

1. Never add manual UTM parameters to Pinterest Ad URLs
2. Let Pinterest append epik automatically
3. Install Pinterest Tag for conversion tracking
4. Use Pinterest Ads Manager for campaign analysis
5. Use GA4 for aggregate traffic and conversion data

Result: Clean, accurate Pinterest Ads attribution without manual work or errors.

Related Documentation:

• Platform Click ID Conflicts
• Pinterest Tracking Validation