Open Flight World vs GeoFS: two browser flight simulators compared

GeoFS is the best-known flight simulator that runs in a browser. It has been flying since 2010, and for many people it was the first proof that you can fly over the real planet without installing anything. Open Flight World does that too, in a browser tab, and I make it.

This page is the case for choosing Open Flight World, made with facts you can check: what the two share, and what Open Flight World adds on top.

What the two share

Both draw the globe with CesiumJS, the open-source 3D globe library, and both run in a browser with WebGL, so there is nothing to install. Both fly in the live weather or in a sky you choose, both put the real air traffic around you, and both work with a keyboard, a mouse or a joystick. Neither asks for an account to fly.

So both are real flight simulators in a tab. What follows is what Open Flight World adds.

At a glance

As of November 2026:

What Open Flight World does best

• Cities in photorealistic 3D. With the HD graphics, the big cities are Google's photorealistic 3D tiles, under volumetric clouds and with soft shadows. In HD a building is solid: fly into one and the flight is over. Over Hong Kong all of this is free; the rest of the planet in 3D is what the unlocks and All Access open.
• The real sky, and the sea too. The aircraft around you are the real ones, a few seconds behind, and so are the ships at sea. With All Access you can start your flight beside a real aircraft that is flying at that moment. How it works is in real-time weather and live air traffic.
• The weather that is outside now. The live weather at the airport you choose, with the sun where it really is, or any sky from clear to storm, fog or snow, at dawn, midday, dusk or night.
• A coach for the first flight. In the simple mode, a coach tells you the next thing to do, from the flaps and the rotation to the flare, with the key or button of the device you are using.
• An autopilot that lands. Every runway has its localizer and a 3° glide path: pick one and the autopilot flies the approach, flares and stops on the centreline.
• Ten aircraft, each with its own cockpit. From the Cessna 172 to the Airbus A380 and the F-16, each one is built with its own 3D cockpit and instruments. All of them, with their figures, are on the aircraft page.
• FlightGear's flight dynamics. Six of the ten fly with JSBSim, the open-source flight dynamics of FlightGear, also used in research, with FlightGear's own files for each aircraft. On top of it the controls answer like a game, so a first flight is easy and a good landing still has to be earned.
• No ads, and no account to fly. You only need an account to buy, and signing in is an e-mail and a six-digit code, with no password to remember.

Pay once, keep it

Open Flight World is free with the Cessna 172 over Hong Kong International, in photorealistic 3D, with no account, no ads and no time limit. What you pay for is the rest of the world: the whole planet in 3D with Google's photorealistic cities, the other nine aircraft and every other airport. Each aircraft or airport can be unlocked once and is yours for good, or All Access opens everything, monthly, yearly or for life. The prices are on the pricing page.

GeoFS is free to fly in the browser, with ads, over two free sets of satellite imagery: one from the Sentinel-2 satellites at 10 to 60 m per pixel, and an experimental AI-enhanced set at 1 m per pixel. Its HD subscription adds sub-metre aerial imagery and removes the ads, and you can try it free for a day once you log in. Its prices are on its HD page.

So the difference is simple: in Open Flight World there are no ads at any level, and what you unlock stays yours.

Take off

The quickest way to see all this is to fly it. Open Open Flight World, take the Cessna off from Hong Kong at dusk in HD, with the city lights coming on under you, and let the coach take you from the runway back to the landing. The beginner's guide to flying in a browser and the controls cheat sheet will help on the way.

If you are weighing the desktop simulators too, see free flight simulators compared, Open Flight World vs FlightGear and a free alternative to Microsoft Flight Simulator.

Sources

GeoFS, checked on 3 November 2026:

• GeoFS home page: ADS-B traffic, real-time weather, CesiumJS.
• GeoFS HD: data sets and subscription plans: the free imagery sets, the ads, the HD subscription and its one-day trial.
• GeoFS instructions: flying without an account, the controls, WebGL 2.0.
• About GeoFS: created in 2010, CesiumJS.

Open Flight World: its features, its aircraft, its pricing and how it is made.

Frequently asked questions