Noticed your Google Search Console (GSC) impressions suddenly dropping since mid-September 2025? You’re not alone. SEO professionals worldwide have been scratching their heads after seeing sharp declines in impressions, shifts in average position, and fewer queries reported, practically overnight.
But here’s the thing, this wasn’t a ranking update or a penalty. It was a reporting change caused by Google’s decision to discontinue the “&num=100” parameter in Search Console data retrieval.
This tweak changes how we interpret search visibility going forward, not your actual performance, but how it’s measured. Let’s break down what happened, why it makes sense, and how you should adjust your SEO reporting from now on.
What Happened — The End of the &num=100 Parameter
The &num=100 parameter previously allowed search tools and crawlers to fetch up to 100 results per query instead of the default 10. This was handy for third-party analytics tools, data scrapers, and even some SEOs pulling deep search data.
In mid-September 2025, Google quietly removed support for this parameter, and that’s when the impression numbers started to tumble.
Here’s the key point:
- Actual search rankings didn’t change.
- Only the way impressions were counted changed.
In simple terms, Google just cleaned up the data. Those “missing” impressions? They weren’t real users, they were inflated counts coming from bots and automated systems.
Why This Change Makes Sense
Honestly, this update was long overdue.
Google’s goal here was to simplify reporting and reflect real human behavior, not data from automated tools. When SEOs or third-party platforms pulled hundreds of results at once, it generated fake impressions that didn’t represent genuine visibility.
By cutting it down to 10–20 results per query, GSC now provides a more accurate, user-focused dataset.
Think of it like decluttering your analytics, fewer numbers, but cleaner and more meaningful ones.
Sure, it disrupted many SEO dashboards and rank-tracking tools, but in the long run, it benefits everyone. It gives us a truer picture of how people actually see (and interact with) our content.
The “Alligator Effect” and Its Closure
If you’ve been following SEO trends this year, you probably heard about the “Alligator Effect.”
Back in early 2025, SEOs noticed a weird pattern: impressions were climbing steadily, but clicks stayed flat. On charts, it looked like an alligator’s mouth opening wider, hence the name.
Many believed this was due to AI Overviews, zero-click searches, or Google’s experimental result formats. But after Google removed the &num=100 parameter around September 12, 2025, impressions dropped sharply, and the alligator’s mouth finally closed.
What this revealed was eye-opening:
Those inflated impressions weren’t coming from real user searches. They were likely triggered by automated crawlers, APIs, or even LLM systems (like ChatGPT) scraping search results.
So the September drop didn’t signal a loss of visibility. It simply corrected months of over-counted, artificial impressions.
What This Means for SEO Reporting
Now that GSC impressions are “clean,” it’s time to adjust how you read your data.
- GSC is still the most accurate source of search performance data.
- But you’ll need to annotate reports to mark when the change occurred, around September 13, 2025.
- Treat everything from that date forward as your new baseline.
Suggested Annotation Example:
“From 9/13/2025 onwards, GSC stopped supporting the &num=100 parameter, resulting in removal of impressions generated by third-party crawlers. Current data reflects true user search visibility.”
That little note will save you hours of explaining sudden impression drops to clients or managers.
How to Adjust Historical Data
Depending on how deep your SEO reporting goes, here are two ways to handle the shift:
Option 1: Simple Method
- Use pre-February 2025 data (before inflated impressions began) as your baseline.
- Ignore the inflated February–September period.
- Resume normal trend tracking from September 13, 2025 onward.
This method works perfectly for most brands and agencies.
Option 2: Advanced Method
If you’re working with large-scale analytics or automated dashboards, you can:
- Analyze click vs. impression ratios across the affected period.
- Identify abnormal spikes between February and September 2025.
- Apply a correction factor to smooth out historical trends.
Either way, make sure your new reports reflect post-update data as the standard.
What to Expect from GSC Going Forward
Here’s the good news:
Now that the data is “clean,” things will look more stable (and realistic).
- Impressions will stabilize at lower but accurate levels.
- Average positions may appear slightly better due to fewer irrelevant impressions.
- Top 20 queries will show up more consistently.
- Clicks and traffic won’t change, meaning real user engagement is intact.
In short, the sky isn’t falling, your reports just got smarter.
Why Impressions and Average Position Still Matter
Even after this change, impressions and average position remain vital metrics for understanding visibility trends.
Here’s why:
- They help identify new ranking opportunities.
- They show how often your brand appears where users actually look.
- And now, they’re free of bot noise and third-party distortions.
So yes, your impression graph might look smaller, but it’s now a lot more trustworthy.
How to Handle SEO Reports After the Change
To keep things transparent (especially for clients), do this:
- Annotate your reports to explain the change clearly.
- Reassure stakeholders that the drop is due to data calibration, not a loss in performance.
- Avoid comparing pre-Sept 2025 data with current numbers.
- Use post-September data as your new benchmark for search visibility.
When you frame it this way, the “drop” becomes an upgrade in accuracy, not a setback.
The Bigger Picture — SEO in the AI & Data Accuracy Era
Let’s zoom out for a second.
Between AI Overviews, LLMs, and zero-click searches, Google’s evolving ecosystem is transforming how we measure visibility. The &num=100 removal is part of a bigger shift toward data precision over data volume.
This update reminds SEOs to focus less on vanity metrics and more on meaningful engagement. The cleaner data in GSC helps us understand what real humans are searching for, not what automated systems are simulating.
A Clearer Baseline for Search Visibility
Google’s removal of the &num=100 parameter marks a major step toward accurate impression reporting.
Search visibility metrics now reflect real human searches, not inflated crawler data.
So if your GSC impressions took a dive, don’t panic, celebrate it. You’re now seeing the truth behind your search presence.
Going forward, reset your benchmarks, recalibrate your dashboards, and build your SEO strategies around authentic user visibility.
Because in the world of AI-driven search, clarity beats quantity every time.
