Life & fun · alternatives · 2026
24 alternatives to SpaceSim
Explore a free 3D space simulator in your browser. Travel across the Solar System, change time, inspect source-backed worlds, and collect postcards.
SpaceSim is a free, browser-based 3D space simulator that lets users explore the Solar System without signing up. Visitors can travel through a UTC-driven universe, observe real NASA ISS trajectories, adjust time, and… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Prices are shown for the 3 we have checked on their own sites, 3 of them free or with a free tier.
- 1GI
Just for fun and self education, I've built this over a weekend to teach myself why orbits exist, not just show planets going around. Something that was never clearly explain to me in school. It opens with a guided tour that builds the idea up step by step: two bodies and the equal/opposite force, inertia (the Sun is removed and Earth just drifts straight), then "an orbit is falling and continuously missing," cosmic velocities with a little rocket, Voyager 1 & 2's real gravity assists (the clock runs the actual 1977–1989 dates so the planets orbit into their grand-tour alignment and the…
Jun 2026 · qunabu.github.io · its alternatives →
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Atlas of Spacefree▲770Hello HN! Sharing a recent side project of mine, the Atlas of Space, that I built out to explore the Solar System. As a long-time space nerd, I realized recently that I didn't have a good intuition on the scale, speed, and relative orientation of the celestial bodies around us. So over the break I built out a kind of spatial Wikipedia to click around and learn about planets, moons, asteroids, and other bodies orbiting the Sun. The physics is all simulated in the browser using simple Newtonian mechanics. There's a lot left to do from here, including modeling objects in non-Keplerian orbits…
2025 · atlasof.space · its alternatives →
- 3MD
2020 · callumprentice.github.io · its alternatives →
- 4
Hello, I am the creator and maintainer of Stellarium Mobile. I have been working in my free time for about a year on this new project Galaxium, that is more about traveling in the universe rather than looking at the sky from Earth. It is still experimental, and at the moment I am not sure what it will become. Feedback is welcome.
Aug 2026 · galaxium.app · its alternatives →
- 5IM
I made this site using R3F (https://github.com/pmndrs/react-three-fiber), a React renderer for 3JS (https://threejs.org/). The celestial bodies are Three.JS meshes. I used loaders (namely 'useLoader' from R3F and 'GLTFLoader' from 3JS) to import 3D models, such as International Space Station. More on loading models in R3F: https://docs.pmnd.rs/react-three-fiber/tutorials/loading-mod... I've future plans for this side project. It would be great to hear from the HN community before diving into them. Enjoy! P.S: Getting an empty…
2022 · spaceinbrowser.com · its alternatives →
- 6
This is a little hobby project that I hope you enjoy. You can see where the International Space Station is now, with live HD video from NASA, on a realistic 3D globe. The positions of the sun and moon are also accurate, though distances aren't to scale. The clouds are also near-realtime; I span that out into a separate project at https://clouds.matteason.co.uk, where the cloud images I create from EUMETSAT data are freely available. I've got more features almost ready to go, like the ability to turn off all UI, toggleable clouds and turning off the day/night cycle I'd love for…
2024 · iss.matteason.co.uk · its alternatives →
- 7
I didn't realize Universe Sandbox ran on MacOS, and I was in the mood to play around a bit. Some functions it's got: - Random system generation - Sonification is super fun too - Habitability Simulation (Just for fun, don't cite this please) - Replacing, spawning, deleting objects I've had tons of fun building this, so I hope someone else can share the joy. It's free and runs in the browser. I'd love to hear any feedback. I think this is at a state where I might leave it as it is, but if people are interested in other features, maybe I'll keep working on it. I've kept saying I'll stop working…
Dec 2025 · luna.watermelonson.com · its alternatives →
- 8
Pilot the SpaceX Dragon 2 vehicle to the ISS!
2020 · iss-sim.spacex.com · its alternatives →
- 9HO
3D gravity and space Simulator. Explore and play around with the force of gravity in the context of an array of scenarios from our solar system and beyond. You can add planets, delete the Sun, change the value of the gravitational constant or simply lean back and enjoy the dazzling beauty of the pen
2018 · thehappykoala.github.io · its alternatives →
- 10WI
Special relativity simulator in which light crawls along at a human speed, so Lorentz contraction, aberration and Doppler shift happen at walking pace.
Sep 2026 · rivendell.dmitrybrant.com · its alternatives →
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AstroGrid▲113Explore the entire universe in your browser, in real 3D
Apr 2026 · velonspace.com · its alternatives →
- 15IB
2022 · multiplanetary.website · its alternatives →
- 16
Fully automated SpaceX ISS Dragon docking simulator system. - danirukun/spacex-iss-docking-sim-autopilot
2020 · github.com · its alternatives →
- 17
AstraPixelsfree tier, from $5/mo▲267A pixel-art solar system at its real current positions.
Aug 2026 · astrapixels.com · its alternatives →
- 18
An open world starship simulator (Early Access Game)
2015 · store.steampowered.com · its alternatives →
- 19
Second only to working at Space X
2015 · kerbalspaceprogram.com · its alternatives →
- 20
A 3D universe explorer & astronomy app, in your browser
Jun 2026 · space.pointdynamics.com · its alternatives →
- 21
Gravity WebGL experiment in the Solar System
2016 · github.com · its alternatives →
- 22
Hi HN! I'm working on an open-world multiplayer space sim with submarine-warfare-inspired combat. Crew a ship, haul cargo, run heists, hunt your foes with passive and active sensors. Browser-based, free, no install. Some of its features: - Submarine-style passive sensors. Contacts start as a bearing line (direction, no distance), resolve into an uncertainty circle, then into a full track. You triangulate over time by moving. - Silent running. Cut your emissions and witnesses can't ID you. - Newtonian flight. No drag, no auto-brake. Flip 180° and burn to stop. - Boarding combat. Dock with…
Apr 2026 · everestdrive.io · its alternatives →
- 23
PixelSpace▲68A tediously accurate scale model of the solar system
2014 · joshworth.com · its alternatives →
- 24
Also compare
- Gravity – Interactive solar-system simulator, from Newton to Einstein alternatives
- Atlas of Space alternatives
- My daughter and I made a site to explore the photos from the ISS alternatives
- Galaxium, an experimental WebGPU space explorer alternatives
- I made a site where you can travel in space in your browser alternatives
- Beautiful 3D ISS tracker with live video and near-realtime clouds alternatives
Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →