SEMrush Sensor
Algorithm TrackingGoogle algorithm volatility tracker and SERP fluctuation monitor
Overview
SEMrush Sensor emerged in 2016 as one of the first free tools dedicated to tracking Google algorithm volatility. Built by SEMrush using data from their massive keyword database, it monitors daily SERP fluctuations across 100,000+ keywords to identify when Google deploys algorithm updates. The tool provides a simple 0-10 volatility score that has become a standard reference point for SEO professionals tracking algorithm activity.
Unlike comprehensive SEO platforms, SEMrush Sensor serves a single purpose: detecting algorithm turbulence before it shows up in your analytics. It's particularly valuable because it operates independently of your website's performance, providing market-wide visibility into SERP stability. The tool gained prominence during major core updates where SEOs needed early warning systems to distinguish algorithm impacts from other ranking factors.
SEMrush Sensor competes directly with MozCast and the Panguin Tool, but differentiates itself through industry-specific tracking and broader keyword coverage. While tools like Sistrix offer algorithm correlation features within paid platforms, SEMrush Sensor remains the most accessible free option for pure volatility monitoring.
Key features
Daily Volatility Tracking
Monitors SERP fluctuation levels across 100,000+ keywords daily, providing a volatility score from 0-10 that indicates algorithm activity.
Industry-Specific Data
Breaks down volatility by 20+ industries including health, finance, travel, and technology to identify sector-specific algorithm impacts.
Desktop vs Mobile Analysis
Separate volatility tracking for desktop and mobile SERPs, helping identify device-specific algorithm changes.
Historical Timeline
Access to historical volatility data going back several years, allowing correlation with known Google updates and traffic changes.
Real-Time Alerts
Visual indicators and trend analysis showing when volatility spikes suggest major algorithm deployments.
Pricing
| Plan | Price | Includes |
|---|---|---|
| Free Access | $0 | Daily volatility scores, industry breakdowns, historical data, mobile and desktop tracking |
FAQ
How accurate is SEMrush Sensor at detecting Google updates?
SEMrush Sensor tracks volatility across 100,000+ keywords and typically shows spikes within 24-48 hours of major algorithm rollouts. However, not all volatility indicates confirmed updates, and some minor updates may not register significant spikes.
What volatility score indicates a major Google algorithm update?
Scores above 7-8 typically indicate significant algorithm activity, while scores above 9 often correlate with major core updates. Daily fluctuations between 3-5 are normal SERP variations.
Can I use SEMrush Sensor without a paid SEMrush account?
Yes, SEMrush Sensor is completely free and doesn't require a paid SEMrush subscription. You can access all volatility data, industry breakdowns, and historical trends at no cost.
How does SEMrush Sensor compare to MozCast for algorithm tracking?
Both tools track SERP volatility effectively, but SEMrush Sensor offers more granular industry breakdowns and covers more keywords. MozCast provides weather-themed scoring and focuses more on feature-rich SERPs.
Should I panic when SEMrush Sensor shows high volatility?
High volatility indicates algorithm activity but doesn't predict ranking impacts for your specific site. Use it as an early warning system to investigate traffic changes and avoid making hasty SEO decisions during volatile periods.
Review Sentiment
Bottom line
SEMrush Sensor is free and worth exploring for SEO managers — free daily SERP volatility monitoring across 25+ industry categories. Still too new for formal reviews, so set expectations accordingly.
People love
- +Free daily SERP volatility monitoring across 25+ industry categories
- +Personal score feature measures volatility impact on your specific tracked keywords
- +Historical data helps identify patterns in Google algorithm update timing
Common complaints
- –Volatility data alone cannot identify the specific nature of algorithm changes
- –Industry categories are broad — may not reflect volatility in your specific niche
- –No alerts or notifications — requires manual checking of the dashboard
Last updated Feb 2026