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Head-to-head · Google Algorithm Tracking Tools

MozCast vs Similarweb SERP Seismometer

  • Updated Nov 2026
  • Both researched from official sources
  • 3 checks side by side
Higher score MozCast #3 in Google Algorithm Tracking Tools 8.8/10 Free plan Free plan✓ 2 of 3 features Visit MozCast
Similarweb SERP Seismometer #4 in Google Algorithm Tracking Tools 8.6/10 Free plan Free plan✓ 1 of 3 features Visit Similarweb

MozCast leads on 0 checks, Similarweb SERP Seismometer on 0, and 3 are even. Who comes out ahead on the 3 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreMozCast · 8.8/10
  • Free planboth
  • Most featuresMozCast · 2 of 3

MozCast scores higher on our rubric for google algorithm tracking tools: 8.8 against 8.6 out of 10; our editors rank them #3 and #4.

MozCast is the better fit for free monitoring of Google ranking turbulence. Similarweb SERP Seismometer is the better fit for free desktop and mobile SERP volatility monitoring.

  • MozCast fits best

    Free monitoring of Google ranking turbulence

  • Similarweb SERP Seismometer fits best

    Free desktop and mobile SERP volatility monitoring

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Side by side

Feature MozCast 8.8/10 Visit ↗ Similarweb SERP Seismometer 8.6/10 Visit ↗
At a glance
Editor score 8.8 8.6
Ranking #3 in Google Algorithm Tracking Tools #4 in Google Algorithm Tracking Tools
Best for Free monitoring of Google ranking turbulence Free desktop and mobile SERP volatility monitoring
Pricing model Free Free
Starting price Free plan Free plan
Free plan ✓ ✓
Free trial — —
Deployment Cloud Cloud
Platforms Web Web
Features MozCast 2/3 · Similarweb SERP Seismometer 1/3
Update alerts Not checked yet Not checked yet
Volatility index ✓ ✓
SERP feature tracking ✓ (best) Not checked yet
Specs
Location views Multiple Not checked yet
Device views Not checked yet Both
History retention Not checked yet Not checked yet
Our review
Pros
  • Shows daily ranking turbulence as an easy-to-scan temperature
  • Compares page-one results across 10,000 hand-picked keywords
  • Tracks SERP feature changes and keeps a history of volatility readings
  • Tracks daily volatility across 10,000+ monitored domains and keywords
  • Shows separate desktop and mobile volatility views
  • Includes risk levels and 30- and 90-day averages
Cons
  • Tracks a hand-picked keyword set rather than your own rankings
  • Samples cities in the United States, not a broad set of locations
  • Monitors turbulence rather than providing a full rank-tracking suite
  • Does not track individual site rankings
  • Focuses on volatility rather than broader SEO work
  • Available as a web tool, with cloud deployment
Our verdict

MozCast turns day-to-day changes in Google’s organic search results into a daily temperature, giving marketers a public way to monitor ranking turbulence. It compares page-one results with the previous day across a hand-picked set of…

Read the review →

Similarweb SERP Seismometer is a free web tool for SEO professionals and site owners who want to spot periods of turbulence in Google search results. It monitors fluctuations across more than 10,000 domains and keywords daily, then…

Read the review →
  1. MozCastGoogle Algorithm Tracking Tools 8.8Free plan
  2. Similarweb SERP SeismometerGoogle Algorithm Tracking Tools 8.6Free plan

Strengths and trade-offs

  • MozCast — where it wins

    • Shows daily ranking turbulence as an easy-to-scan temperature
    • Compares page-one results across 10,000 hand-picked keywords
    • Tracks SERP feature changes and keeps a history of volatility readings

    Where it doesn't

    • Tracks a hand-picked keyword set rather than your own rankings
    • Samples cities in the United States, not a broad set of locations
    • Monitors turbulence rather than providing a full rank-tracking suite

  • Similarweb SERP Seismometer — where it wins

    • Tracks daily volatility across 10,000+ monitored domains and keywords
    • Shows separate desktop and mobile volatility views
    • Includes risk levels and 30- and 90-day averages

    Where it doesn't

    • Does not track individual site rankings
    • Focuses on volatility rather than broader SEO work
    • Available as a web tool, with cloud deployment

MozCast vs Similarweb SERP Seismometer: questions

Which is better for google algorithm tracking tools, MozCast or Similarweb SERP Seismometer?

MozCast scores higher on our rubric for google algorithm tracking tools: 8.8 against 8.6 out of 10; our editors rank them #3 and #4.

How do MozCast and Similarweb SERP Seismometer compare?

All 3 checks we put side by side come out level: neither leads on any.

Do MozCast and Similarweb SERP Seismometer have a free plan?

MozCast: Yes. Similarweb SERP Seismometer: Yes.

More comparisons

All google algorithm tracking tools comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Nov 2026

Last updated · How we research and update