Comparison

Universe Size Comparison vs Solar System Viewer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Universe Size Comparison

Explore the vastness of space and understand celestial body dimensions through interactive 3D comparisons. Discover the scale of planets and stars, from our Sun to hypergiant stars, with guided tours and free comparison modes.

Highlights
  • 3D astronomical comparisons
  • Tour Mode with guided explanations
  • Free Mode for custom comparisons
  • Scale comparisons of planets and stars
  • Detailed celestial body information
  • Elegant user interface
Features
Read full description

Universe Size Comparison is a unique 3D astronomical app that will make you understand the real dimensions of the universe and how small we are. Have you ever wondered how big the Sun is compared to Earth? Or what is the largest planet between Mars and Earth? Do you want to find out the dimensions of some of the most famous stars in the sky like Rigel and Betelgeuse in comparison to our Sun? Do you want to compare everything with the hypergiant star VY Canis Majoris? Universe Size Comparison is the right app for you. The app offers two modes: Tour Mode and Free Mode. Tour mode will guide you on a spectacular journey where you will see planets and stars compared in full scale. All accompanied by simple and clear explanations regardless of the level of knowledge of the subject. The Free mode will allow you to compare two celestial bodies of your choice in scale. You will also find out more information on the bodies you are comparing thanks to an elegant user interface designed to offer the maximum user experience.

About

Solar System Viewer

Explore and simulate the orbits of planets in our solar system. This app allows you to speed up or slow down time, travel to any date, and view planetary positions. It also offers widgets for your home screen and Apple Watch complications.

Highlights
  • Simulate planetary orbits
  • Adjust time speed
  • Time travel to specific dates
  • Home screen widgets
  • Apple Watch integration
  • View planet overviews
Features
Read full description

8Planets is a simple viewer and simulator for planetary orbits in our Solar System. 8Planets helps you discover how the planets aligned and move around over time so that you feel the scale of the Solar System or even the Universe. By giving you quick and easy access to the Solar System everywhere, 8Planets will make you feel that the Solar System is close to us. FEATURES ・Planetary Motion Speed up or slow down time to see how the planets rotate over time and grasp the scale of the Solar System. ・Time Travel Travel back or forward in time to view the Solar System or planetary positions on any given date. ・Widgets Widgets allow you to display the real-time Solar System on your Home Screen. ・Watch View the Solar System on your wrist and use Digital Crown to travel back or forward in time. ・Others Apple Watch Complications, Overview of the planets, Option to show Pluto, Sharing your favorite moment of the Solar System, URL Scheme, and more.

Screenshots

Universe Size Comparison4 screens
Solar System Viewer3 screens

Verdict

The call

The clearest difference is rating: Solar System Viewer at 4.4 against Universe Size Comparison's 3.2. Solar System Viewer also leads on review sentiment (83% vs 70%). Universe Size Comparison's advantage is in-app purchases (none vs 4) and price ($1.99 vs $2.99). On ratings volume, update cadence, ads and monetization model there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Universe Size Comparison costs $1.99 and Solar System Viewer $2.99 up front. Solar System Viewer sells 4 one-off in-app purchases. Universe Size Comparison asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Solar System Viewer holds the better App Store score, 4.4 against 3.2. Both are backed by a comparable volume of ratings — 30 and 28 respectively. Written reviews point the same way: 70% of Universe Size Comparison's written reviews are positive against 83% of Solar System Viewer's.

UpkeepUpdate frequency

Universe Size Comparison ships an update every 3 months, Solar System Viewer every 2 months. The most recent releases landed on November 3, 2026 and November 7, 2026 respectively.

Scorecard5 real differences · 5 level
Universe Size Comparison versus Solar System Viewer: the parameters behind the verdict, then further details
ParameterUniverse Size ComparisonSolar System Viewer
Price$1.99 — better$2.99
Rating3.2 (30 ratings)4.4 (28 ratings) — better
Positive reviews70.0% of reviews83.3% of reviews — better
Number of ratings30 — better28
Update frequencyEvery 3 monthsEvery 2 months — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidPaid
DevicesiPhone, iPad, Apple TViPhone, iPad, Mac, Apple Watch — better
Requires iOS17.0 — better26.0
Further details — not scored
Size411 MB22 MB
Age rating+44+
DeveloperDaniele CitiBLUE COMET LABS LLC

Customer experience

Universe Size Comparison

All ratings30 ratings
Positive46.7%
Neutral20.0%
Negative33.3%
Written reviews10 reviews
Positive70.0%
Neutral30.0%
Negative0.0%

Solar System Viewer

All ratings28 ratings
Positive85.7%
Neutral3.6%
Negative10.7%
Written reviews6 reviews
Positive83.3%
Neutral16.7%
Negative0.0%

In-app purchases

None

Universe Size Comparison

No in-app purchases

4 purchases

Solar System Viewer

One-time4
  • Io Tip$1.99
  • Europa Tip$3.99
  • Ganymede Tip$5.99
Show 1 more
  • Callisto Tip$9.99

Questions

Is Universe Size Comparison free?
Universe Size Comparison costs $1.99, with no in-app purchases.
Is Solar System Viewer free?
Solar System Viewer costs $2.99, and also offers in-app purchases.
Which has better reviews, Universe Size Comparison or Solar System Viewer?
Solar System Viewer is rated higher. Universe Size Comparison averages 3.2 out of 5 from 30 ratings, while Solar System Viewer averages 4.4 from 28 ratings.
Do Universe Size Comparison or Solar System Viewer have ads?
Neither Universe Size Comparison nor Solar System Viewer shows ads.
Which is updated more often, Universe Size Comparison or Solar System Viewer?
Universe Size Comparison ships an update every 3 months, and Solar System Viewer every 2 months. Most recently, Universe Size Comparison was updated on November 3, 2026 and Solar System Viewer on November 7, 2026.

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