Questions, answered.

Yes. The app is free to use: the simulator, the puzzles, the Layout Designer and the parts list cost nothing, with no time limit. Only the AI features use AI Credit, and your first $5 of it is on us. Add more only if you want it, in packs from $5. No subscription. See Pricing.

An account is how you get into the simulator, and it's free. It keeps modelrailsim running for real modelers rather than bots, and it carries your layouts, saves and settings from one device to another. Signing in with Google or Apple takes one click.

No. It runs in a modern browser (Chrome, Edge, Safari or Firefox) on a computer, a tablet or a phone. On a phone it has a layout of its own: the board fills the screen, the menu slides in from the left, the cards from the right, and the controls you use most open from a bar along the bottom.

Both, your choice. The ◐ button at the top of every page sets the theme and the units, and the simulator follows it: millimeters and km/h, or inches and mph.

Yes. The tour walks you through driving, the points and coupling in about two minutes, and every key and mouse action is listed under the keyboard button at the bottom right. Hover over anything on the layout to see what it is.

An on-screen NCE Power Cab or a Digitrax DT602, key for key: select a loco by its number, set its speed and direction, throw turnouts by accessory number, make consists and run macros. Or drive with the mouse and keyboard.

Yes. Press 3D on the board and the plan becomes the layout on its table. The View card has eleven viewpoints: from the top, the cab, beside the track, chasing the train, from the points of the turnout ahead, and more, and 🎬 Cinema cuts between them on its own. Save a view you like to come back to. Everything still works in 3D: throwing turnouts, uncoupling, placing cars.

Plenty. Drive with the arrow keys, F and R, Space and H for the horn; 1 to 6 throw the points. Shift + a letter opens or closes each card (each card shows its key beside its title), and ? lists them all.

Yes. Drag the corner at the board's bottom right to size it, and its edge to move it; the cards can sit round it. Fit to window in Display Options puts it back.

Yes, with an NCE Power Cab and the NCE USB Interface, in Chrome, Edge or Brave on a computer (nothing to install). Open the Real layout card in the simulator (Shift + H), plug the USB Interface into the Power Cab panel's cab-bus jack and the computer, and press Connect. From then on the on-screen Power Cab, the keyboard and the Conductor send real DCC commands: a mapped loco's speed, direction and F0–F2, and every turnout you throw on the plan, with its accessory number. Set the handset down while connected: the Power Cab can't tell the computer what its knob is doing, so the sim is the only throttle; whatever you do on the handset the sim won't know about. Stop all e-stops every mapped loco, and unplugging or closing the tab stops them first where it can. Nothing is written to decoders, and the card's log never leaves your browser. Digitrax, JMRI and phones are on the roadmap. Step by step: Real layout setup and Real controller setup. The dongle is in the store.

Yes: the diesel engine, bell and horn, the steam locos' exhaust, whistle and bell, and the couplings are real recordings, not synthesized noises. A steam loco beats four times to a turn of its drivers, so the beat follows the wheels.

Two classic shunting (switching) puzzles. In the Inglenook you make up a train of five cars, in order, from eight scattered across three short sidings, with a headshunt that only holds a few cars at a time. In John Allen's Timesaver you deliver cars to five industries on a deliberately awkward little layout. Both reward planning more than speed.

By moves (each time the loco sets off in a new direction) and time, against the fewest moves the draw can be done in. The finish summary shows your efficiency and an AI review of the run, and your best goes on the Leaderboard. Only runs you drive yourself are ranked.

The whole layout, not just the track. Track: anything you could build from sectional or flex track, in 39 track systems from 18 makers plus handlaid track, in T, Z, N, HO/OO, HOn3, O and G scale, with their real geometry and part numbers: straights, curves, turnouts, curved turnouts, wyes, three-ways, crossings, slips, crossovers, bridges, helixes, ramps and accessories. Scenery: buildings, roads, level crossings, yards, water, rivers, woods, trees, hills and mountains with tunnels, fences, and signals. Rolling stock: locos and cars at real lengths, with siding capacities and clearances. The board: its shape, surface and color, and the benchwork under it. The wiring: feeders, insulated joiners and auto-reversers, and the DCC hardware under the board (an NCE or Digitrax command station, boosters, breakers, detectors and accessory decoders) with the bus and drops. See the Layout Designer.

Yes. The Scenery card puts buildings (a house, a station, a factory…), roads, paved yards and parking lots, water, rivers, woods and single trees, hills and mountains, fences, and signals on the board. Where a road crosses track, the level crossing is added for you, and where track runs into a hill or a mountain, it gets a tunnel with portals. Turn and size anything with its handles. It all shows in the 3D Preview and the simulator, and AI can place scenery too when you ask.

Yes. The Construction card draws the tables the layout sits on (drag one out, or click its corners), with the frame and legs in 3D, and the board's surface: plaster, meadow, forest, desert, soil, plywood, snow or any color. Drill marks holes for feeder wires, Carve takes material out to a depth for a lake or a valley, and Cut out opens the board right through, framed underneath, for a helix or an underpass. Add dimensions, lines, circles and notes; they print with the plan.

No. Building by hand is just as complete: drag pieces from the Parts Catalog, draw a line and let real pieces be laid along it, or draw over a picture of a plan. AI is there when you want it, and you can mix the two: many people build by hand and ask AI to finish the tricky bits, like joining two ends to close a reverse loop.

Yes, and you don't have to work out the pieces or the math. The Layout Objects card has three ready-made objects, each built from your system's real pieces: a helix (choose the radius and the turns, and it climbs with the clearance your trains need), a ramp from one height to another at the grade you set, and up, level, down over a bridge and back. Each shows its length, rise and grade as you change it. Drag it onto an open end and it's laid in one go, and afterwards it moves as one object. To shape any run of track yourself, right-click it › Track settings.

Yes. Choose the board's shape as you start: a rectangle, an L, a U, a square donut round the walls, or your own outline. Drag its handles to size it. Print… gives the plan on one page to scale, or 1:1, tiled across sheets with overlaps and trim lines, to tape together and lay track on. And you can put a photo or sketch of the room itself under the board, mark the posts, the furnace and the doors, and plan the board against them with the aisles checked.

Yes. In the Layout Designer, choose another system in the track system menu, even with track laid, and your track is rebuilt in the new system's pieces, following how it's joined: turnouts, sidings and loops stay where they were, and between scales (N to HO, say) the layout grows or shrinks so trains and sidings keep their size. The pieces of different systems aren't the same sizes, so a loop may no longer quite meet: you're offered Try to fix, which adjusts the straights, curves and turnouts already there to close it; anything left is listed in the Info card, and the Planner can help. Undo switches back.

XTrackCAD (.xtc) and AnyRail (.any) open piece by piece: Import › Layout file in the Layout Designer matches each piece to the same track system here and places it where it was; anything that can't be matched is listed. WinTrack's own files are a closed format, so export a DXF from WinTrack (File › Export) and open that: its lines sit on the board at the right size to trace over, like any DXF from a CAD program. Export saves a design out as an XTrackCAD file, or as a DXF with the centerlines, rails, board and labels on their own layers for CAD and the laser cutter.

Yes. Import › Layout file opens an AnyRail layout (.any) too: each piece is matched to the same track system here and placed on its ends, flex track as flex, and anything that can't be matched is listed.

Yes. In the Layout Designer, Export › Share link makes a link anyone can open, no account needed: the plan and its parts list, and a button to open a copy in the Layout Designer.

Yes, in the 20 systems that make it. Bend it as you would a curve in a drawing program, with the radius shown as you go.

Yes. Give any run of track a height, a ramp, or up, level and down at the grade you choose, or drop in a ready-made helix. Grades over 2.5% get a note and over 3% a warning, and track crossing track needs the scale's clearance. The 3D Preview shows it as it'll be.

Yes. Two-rail track shows its polarity as red and black rails. Place feeders, insulated joiners and auto-reversers yourself, or let the Designer work them out: a reverse loop gets its joiners and reverser, every section a feeder.

Straight away. Save, and the design opens in the simulator wired and ready to drive. The 3D Preview runs it right inside the Designer while you build.

Export saves a layout as a file to send to someone, and Import opens one. Parts List / Buy Parts (in the simulator's dock, or a card in the Layout Designer) is a shopping list of every piece by part number, with the packs to buy and the price, and what you still need after what you have. Under Buy from, choose a country and a store: each part links to it there, and a store with its own prices here shows them in a column beside the maker's list price.

Describe a layout (“a 1600 × 800 oval with a passing siding and two spurs”) or show it a picture of a plan, and it lays real pieces with the same tools you have, checks gaps, grades and wiring, and tells you what it did. It keeps what you built by hand, and every change it makes can be undone. Stuck joining two tracks? Closing a gap between two ends, such as finishing a reverse loop, can take awkward piece-by-piece fitting by hand. Ask AI to finish it (“join the ends at p12 and p30”, “close the reverse loop”): it works out the pieces that fit, lays them, and adds the loop's insulated joiners and auto-reverser.

AI features (the Planner, the Conductor, puzzle help, the end-of-puzzle review) use AI Credit. Every account gets $5 of it once its email is confirmed (or straight away with Google or Apple sign-in). Each request uses a little: more for a big layout, a picture, a long conversation or higher thinking. The AI gauge shows what's left and turns from green to red as it runs down. Add more from the gauge in packs from $5 to $250; bigger packs include a bonus. Credit never expires, and payments are handled securely by Stripe. Building by hand, driving and the puzzles themselves are free and never use credit.

Yes, from a store marked takes orders in the Buy from menu of Parts List / Buy Parts. Send order sends your list of what's still to buy, with your name and email, to the store. The store contacts you to confirm it, take payment and ship it; nothing is charged on modelrailsim. Your orders are listed on your Account page. More stores are joining: any store can link to its own parts today.

Yes. Post about modelrailsim on social media and email a screen capture of the post, with your username, to social@modelrailsim.com: we add $1 of AI Credit for each one, usually within 24 hours. Testers who try new features and report what they find get AI Credit too (write to testers@modelrailsim.com). See the Messages at the top of this page for how.

Yes. Payments go through Stripe's secure checkout. Your card details go straight to Stripe: we never see or store them. Your Account page lists every purchase with its Stripe receipt, and what your AI requests used.

If a purchase goes wrong (the credit isn't added, or you were charged twice), email billing@modelrailsim.com and we'll put it right. AI Credit is added as soon as you pay, and in the EU and the UK the 14-day right to cancel ends once it's added, as checkout explains: see the Terms.

Yes, we'd like that. Stores can appear in the parts list for their country, show their own prices, and receive orders by email or straight into their own system. One store per country can be the Featured store, shown with its logo at the top of every parts list there. See the message for online retailers, or write to retailers@modelrailsim.com.

Four are N scale (1:160) on Kato Unitrack: the Inglenook, the Inglenook with Industry Spur, the Timesaver, and Tipple Creek Branch, a U-shaped layout with scenery built in the Layout Designer. The fifth is an HO (H0, as Europe writes it) Märklin C-Track plan. Everything is drawn to the millimeter.

Yes. Your layouts, saved sessions, macros and settings are kept with your account, so signing in on another computer or tablet picks up where you left off.

modelrailsim.com is made by Iron Rod Systems LLC in Salt Lake City, Utah. Questions or ideas? Write to contact@modelrailsim.com or post on the Ideas board. For anything about a purchase or AI Credit, write to billing@modelrailsim.com.