Run XFOIL online: airfoil analysis in your browser
XFOIL is the classic airfoil-analysis tool: powerful, still widely used, but locked behind a command line. Aero Design Studio runs the real solver in a clean browser interface: pick an airfoil, set Reynolds number and angle of attack, and get lift and drag polars, pressure-coefficient plots and boundary-layer transition, with no install and no setup.
XFOIL: from €7 a month with the Plus plan
What is XFOIL?
XFOIL is a program for analysing the aerodynamics of an airfoil, a wing's cross-section. First written by MIT's Mark Drela in the late 1980s, with Harold Youngren, it has been the standard low-speed airfoil tool for decades and still underpins much of how wings are designed today.
It works by combining a fast model of the outer airflow with a model of the thin boundary layer that clings to the surface, and predicting where that layer trips from smooth to turbulent. From that it returns the numbers that matter: how much lift the airfoil makes at each angle, the drag that comes with it, and the pressure acting along the surface. It is accurate, trusted and, until now, awkward to use.
Why XFOIL's command line is so hard, and how we fix it
XFOIL is brilliant, but it was built for a 1980s terminal. To get a single polar you install and often compile it, then drive it by typing terse commands in the right order, manage coordinate files by hand, and read results as columns of raw numbers with no plot. One mistyped keyword and the run quietly fails. For a beginner it is a wall; for an expert it is friction.
XFOIL c> LOAD s1223.dat
XFOIL c> OPER
.OPERi c> VISC 5e5
.OPERv c> ITER 200
.OPERv c> PACC
polar.txt
.OPERv c> ASEQ -5 15 0.5
... read columns by hand ...
- Pick an airfoil from a list, import a .dat, or pull a wing from the Designer.
- Type the Reynolds number and a range of angles, with no command order to memorise.
- Get plotted polars, a Cp chart and transition points, drawn for you.
- Download a clean PDF report. Nothing to install, nothing to break.
Polars, Cp distribution, transition & separation
Every run returns more than a single number. XFOIL sweeps the angle of attack and builds a full polar (lift, drag and moment at every angle), then a set of boundary-layer views show why the airfoil behaves the way it does, from the Cp distribution to where the flow finally lets go.
Cp distribution
Where the suction peak forms and how hard the airfoil is working: the clearest read on how load is built along the surface, and where trouble starts.
Transition
Where the boundary layer trips from laminar to turbulent, on each surface: the point that sets much of the drag.
Boundary-layer health
Momentum thickness and shape factor along the surface: the early warning that shows the flow tiring before it finally lets go.
Separation & stall
Laminar separation and reattachment that quietly costs drag, and the onset of stall at the edge of the envelope.
Multi-element coupling for main-and-flap wings
A race car wing is rarely a lone airfoil. XFOIL on its own analyses one element at a time, so it can't see how a main element and a flap influence each other through the slot between them.
Aero Design Studio closes that gap. It runs each element and couples them, feeding the flow each one sees back into the other and iterating until the result settles, so the figures reflect the wing working as a whole, not two airfoils in isolation. That coupling, and the design-to-CFD pipeline around it, is what sets this apart from a plain browser XFOIL.
From 2D to 3D: estimating real wing values
XFOIL analyses a 2D cross-section, and that section drives most of how a wing behaves, but a real wing has ends, and air leaking around them costs lift and adds drag. Aero Design Studio takes the 2D result and applies a finite-wing correction for your wing's aspect ratio, turning the airfoil numbers into a realistic estimate for the actual wing. You get the speed and clarity of a 2D analysis with a sensible read on what the three-dimensional wing will really do, and when you want the full flow field, the same geometry goes straight to CFD.
How to run an airfoil analysis
No install, no command line, no coordinate files to manage. The whole analysis runs from a few choices in your browser.
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1
Choose an airfoilA NACA, Selig or Eppler profile, your own .dat coordinates, or a wing sent from the Designer.Airfoil
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2
Set the Reynolds numberEnter it for your speed and chord, or let the tool compute it, so the viscous run matches reality.Reynolds
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3
Set NcritChoose the transition criterion: lower for dirty, turbulent air; higher for a clean wind tunnel.Ncrit
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4
Sweep the angle of attackPick a range and let XFOIL build the full polar (lift, drag and moment versus angle) in one run.Sweep
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5
Read and exportRead the polar, Cp and transition on screen, then download a clean PDF report.Report
The real XFOIL engine, checked against the reference
This isn't an approximation of XFOIL. It runs Drela's actual solver: the same linear-vorticity panel method, integral boundary layer and eN transition prediction that practitioners have relied on for decades. To prove it, results are checked against Airfoil Tools' XFOIL, the de facto online reference.
One honest note: XFOIL is a fast, low-speed panel method, and like any such method it is most reliable in the attached-flow range: through the linear part of the lift curve and up toward stall, exactly where you design. Push deep into stall or heavy separation and a full CFD solve becomes the better tool; the two are made to work together.
XFOIL vs CFD
They are complementary, not rivals. XFOIL is a panel method: near-instant and ideal for screening single airfoils in attached flow. CFD solves the full flow field, so it captures separation and the detailed interaction between elements that a panel method can only approximate. The usual workflow: screen fast in XFOIL, then confirm and dig into the real wing in CFD.
| XFOIL | 2D CFD | |
|---|---|---|
| Speed | Seconds | Minutes |
| Single-airfoil screening | Ideal | Heavier than needed |
| Multi-element wings | Coupled estimate | Resolved directly |
| Separated & stalled flow | Limited | Captured |
| Best for | Fast airfoil screening | Confirming the real wing |
Send a Wing Designer wing straight to XFOIL
XFOIL here isn't a standalone widget: it's one step in a connected toolchain. The same project you draw in the Wing Designer can be analysed without redrawing or re-entering a single coordinate.
Design a wing, send it to XFOIL for a fast polar sweep, refine the profile and angle, then push the same geometry to CFD for the full flow field, and export STEP or STL when you're happy. Design, screen, confirm, manufacture, all in the browser. That integration is the point, not the XFOIL wrapper.
Built for Formula Student, FSAE & hobbyists
Formula Student and FSAE teams screen airfoils and back aero decisions with polars in design reports: fast, on a student budget, with nothing to install on shared lab machines. Motorsport hobbyists and track-day builders check a profile before cutting metal, without fighting a terminal. Engineering students and the curious watch how Reynolds number, Ncrit and angle of attack actually move lift, drag and the transition point, learning airfoil aerodynamics by doing, not just reading.
And it isn't downforce-only: aviation and RC enthusiasts can analyse a wing in a lift orientation just as easily: the same polars, Cp distributions and transition data apply whether the airfoil is making downforce on a race car or lift on an aeroplane wing.
What an analysis costs
Without a plan, every run is priced in tokens, and the exact cost is always shown before you confirm. With the Plus or Pro plan, XFOIL is included.
XFOIL: from €7 a month with the Plus planfull polar sweep, Cp, transition & separation in one report
multi-element coupling: each element solved and iterated together
Plus: 100 simulations every 30 days. Pro: 150. Beyond that, runs use tokens.
Token packs start at 30 tokens for €5 (120 for €15, 500 for €50), tokens never expire, and new accounts get free tokens to try the tools. XFOIL is included in the Plus plan (100 simulations every 30 days) and in Pro (150): see the plans. Need the full flow field? CFD pricing is on its own page.
Frequently asked questions
Is this the real XFOIL?
Do I need to install anything?
How do I read an XFOIL polar?
What is Ncrit and what value should I use?
What Reynolds number should I pick?
Can XFOIL handle a 3D wing?
How much does it cost?
Can I download the polar file?
Keep going
Run your first XFOIL analysis
Real XFOIL in the browser: polars, Cp and transition, with a clean PDF report. No install, no command line.