1. User Location
Impact: High
Google uses the user's geographic location (via IP, GPS, or uule) to customize results, particularly for queries with local intent (e.g., “dentist”, “pizza near me”).
Affected areas:
Map pack listings
Local business visibility
Regional news or services
How to control:
Use the uule parameter in search URLs to simulate a specific city or region.
Example:
https://www.google.com/search?q=seo+agency&uule={uule}
2. Language and Interface (hl)
Impact: Moderate
The interface language (hl) and the user’s preferred languages affect which version of multilingual content appears (e.g., English vs French page versions).
Affected areas:
Featured snippets
hreflang resolution
Display language of site links
How to control:
Set hl in the URL:
&hl=en (English interface) &hl=fr (French interface)
3. Country Context (gl)
Impact: Moderate
The gl (Geo Location) parameter defines the country context for the search, which can affect region-specific results.
Affected areas:
National domains (e.g., .co.uk vs .com.au)
Localized versions of international websites
Regional shopping/product listings
How to control:
Use gl=xx (e.g., gl=us, gl=de)
4. Search History & Click Behavior
Impact: Low to moderate
If the user is logged in, past searches, visited websites, and click-throughs can slightly adjust future SERPs.
Affected areas:
Auto-suggestions
Search filters (e.g., shopping preferences)
Result ordering in low-competition queries
How to neutralize:
Use Incognito/Private browsing mode
Log out of Google account
Add &pws=0 (disables personalization)
5. Device Type (Mobile vs Desktop)
Impact: Moderate
Mobile devices may show different results due to:
Mobile-first indexing
Local prioritization
Different featured snippets or layouts
How to test consistently:
Use device emulation in Chrome DevTools or SERP APIs that simulate device types.
6. Time of Day / Freshness Signals
Impact: Low to moderate
Google adjusts results in real-time based on:
News trends
Temporal search intent
Recent events
Example: A search for “apple event” during a product launch week shows different results than two months later.
How to test consistently:
Run SERP snapshots at the same time across test cases. Use stable, non-news queries when possible.
7. Google Account & Personal Profile
Impact: Low (but unpredictable)
Google may personalize results based on account activity, preferences, subscriptions, or Gmail content — especially in verticals like flights, jobs, or shopping.
How to neutralize:
Use logged-out sessions or fresh profiles.
Summary: How to Minimize Personalization in Testing
| Factor | Control Method |
|---|---|
| Location | Use uule or geotargeted tools |
| Country | Use gl parameter |
| Interface Language | Use hl parameter |
| History/Personal Data | Incognito mode, &pws=0, log out |
| Device Type | Use emulator or SERP API |
| Time/Freshness | Snapshot tests consistently |
Conclusion
Understanding and controlling SERP personalization factors is essential for accurate SEO auditing, rank tracking, and competitive analysis. While some variations are inevitable, using parameters like gl, hl, uule, and disabling personalization (&pws=0) allows SEOs to test and analyze search results with far greater consistency and precision.
For more precise location emulation, use the UULE Generator Tool to simulate SERPs from any city or region.