Compare FlightGear vs X-Plane 12 on PC: realism, aircraft, scenery, performance, add-ons and cost, with a clear recommendation for each simmer.
X-Plane 12 is the better PC flight simulator for most people because it provides more consistent aircraft quality, stronger weather and lighting, easier control setup, and a much larger add-on ecosystem. FlightGear is better if you need a genuinely free, open-source simulator, enjoy experimenting with community aircraft, or want to inspect and modify the software itself.
FlightGear vs X-Plane 12 at a glance
The central trade-off is freedom and zero cost against consistency and polish.
| Area | FlightGear | X-Plane 12 |
|---|---|---|
| Cost | Free and open source, with no restricted flying mode | Commercial simulator; a free demo is available for compatibility testing |
| Flight modelling | Supports capable models including JSBSim and YASim, but realism varies sharply by aircraft | Strong aerodynamic modelling with more consistent default aircraft |
| Aircraft | Large community selection of uneven age, completeness and quality | Better default consistency and a deeper freeware and commercial ecosystem |
| Graphics and weather | Functional and configurable, but visual quality varies with scenery and settings | Better lighting, weather presentation, seasonal effects and default visual cohesion |
| Scenery | Worldwide scenery can be downloaded through TerraSync and retained in a local cache | Global regions are installed locally, with stronger default airports and scenery integration |
| Setup | More manual work may be needed for scenery, aircraft and unusual controllers | Generally easier controller calibration, profiles and graphics configuration |
| Platforms | Windows, macOS and Linux | Windows, macOS and Linux |
| Best for | Free flying, open-source development, education and experimentation | Regular home simulation, procedural practice, VR and long-term expansion |
Which simulator has more realistic flight physics?
X-Plane 12 is the safer realism choice overall, but FlightGear is not an arcade game. FlightGear aircraft can use sophisticated flight-dynamics models, particularly JSBSim, and a carefully developed aircraft may behave convincingly. The problem is consistency: every aircraft still depends on the accuracy of its aerodynamic data, systems and cockpit implementation.
X-Plane calculates aerodynamic forces across the aircraft's surfaces, but that method does not make every add-on automatically accurate. Incorrect geometry, engine data or control limits still produce incorrect behaviour. The difference is that X-Plane 12's default fleet and established add-ons provide a more predictable baseline; our explanation of how X-Plane models flight and where its realism stops covers that distinction in more detail.
The mistake we see most often is treating the name of a flight-dynamics engine as proof of realism. Judge the individual aircraft instead: compare published speeds, power settings, stall behaviour, trim changes, fuel use and avionics operation with its real documentation.
For instrument procedures, navigation practice and repeatable aircraft handling, X-Plane 12 is usually the more practical tool. Neither ordinary home installation becomes an approved training device by itself; formal credit requires an authorised combination of software, hardware and operating conditions.
Is FlightGear completely free?
FlightGear is a complete free simulator rather than a time-limited demo, and its source code is available for inspection and modification.
What you give up is not basic access to flight, aircraft or worldwide scenery. You give up some consistency, streamlined installation and predictable add-on quality. Our detailed assessment of FlightGear's strengths and compromises explains what to expect before installing it.
TerraSync can fetch scenery tiles while you fly and cache them for later use. A new installation may therefore show sparse terrain, missing objects or pauses while data arrives. This is usually a scenery-download issue rather than the simulator's final visual quality; follow the correct process for setting up TerraSync and local FlightGear scenery before judging it.
TerraSync should not be confused with continuous photoreal aerial streaming. It supplies FlightGear scenery data, and detail still varies by region. Once the required tiles are cached, they can be used without repeatedly downloading them.
Which runs better on a low-end PC?
Neither simulator is guaranteed to run better solely because FlightGear is free or X-Plane 12 is commercial.
X-Plane 12's clouds, lighting, reflections and dense scenery can place substantial demands on the GPU and processor. FlightGear can be scaled down, but performance varies with the aircraft, scenery, rendering options and background TerraSync activity. Free software does not automatically mean lightweight software.
The reliable comparison is to install FlightGear and the X-Plane 12 demo on the same computer, then test the same resolution, weather complexity and type of airport. Use a simple default aircraft first. If performance is poor, reduce anti-aliasing and resolution for a GPU bottleneck; reduce object density, traffic and complex systems for a CPU bottleneck.
Avoid testing one simulator at a rural airfield in clear weather and the other at a major airport under heavy cloud. That comparison says more about workload than the simulation engine.
Which has better aircraft, scenery and add-ons?
X-Plane 12 has the stronger add-on ecosystem and is the easier platform to expand into a specialised home simulator.
Its selection covers detailed airliners, general aviation aircraft, helicopters, airports, scenery, weather tools and hardware integration. There is also a substantial freeware library; our guide to useful X-Plane 12 aircraft, scenery and utility add-ons separates practical upgrades from unnecessary extras.
FlightGear also offers a broad aircraft catalogue, including unusual and experimental types. Quality is less predictable: one model may have a detailed cockpit and systems, while another has basic instruments, incomplete sounds or behaviour tied to an older simulator release.
Do not assume an X-Plane 11 aircraft or plugin is fully compatible with X-Plane 12. Older scenery often transfers more easily than complex aircraft, but lighting, materials, avionics and plugin code may need an update. Check explicit X-Plane 12 support before building a setup around any add-on.
What common setup problems affect the comparison?
Most bad first impressions come from incomplete scenery, conflicting controller assignments or mismatched add-ons rather than the core simulator.
- Duplicate control axes: If rudder, throttle or brakes move by themselves, clear duplicate assignments from other connected controllers and recalibrate the remaining axes.
- FlightGear scenery still downloading: Allow TerraSync to complete the local area, check that it can write to its cache, and restart at the same airport before assessing detail or stutters.
- Overloading graphics settings: Start with moderate settings and raise one costly option at a time. Maximum settings are not a sensible baseline for comparing frame rates.
- Old aircraft in a new simulator: Use aircraft built or confirmed for the simulator release. Missing instruments and broken systems often indicate incompatibility rather than a general simulator fault.
- Overwriting default files: Keep third-party X-Plane aircraft in a separate folder under
Aircraftand scenery underCustom Scenery. Avoid replacing default content unless an add-on specifically requires it.
Should you choose FlightGear or X-Plane 12?
Choose X-Plane 12 for the best overall PC flight-simulation experience; choose FlightGear when cost, source-code access or experimentation matters more than consistency.
- Choose X-Plane 12 if you want dependable default aircraft, better visuals and weather, VR, serious procedural practice, simpler hardware profiles or a wide upgrade path.
- Choose FlightGear if your budget is zero, you want a complete simulator without a restricted demo, or you are interested in modifying aircraft, flight models and the simulator's code.
- Test both first if PC performance is the deciding factor. FlightGear costs nothing to evaluate, while the X-Plane 12 demo provides a realistic check of controls, graphics compatibility and frame rate before purchase.