onRails – Getting Started

When onRails opens, you land on the Launcher. This is home base — from here you pick a module, check your sim connection, and adjust settings. Nothing here affects your sim; onRails only reads telemetry, it never writes to your game.

The first time through, a short spotlight tour points out the two module cards and the sim status strip. Click Got It to dismiss each step, or Skip All to jump straight in.

The strip near the bottom of the Launcher lists every sim onRails supports. Launch your sim and load into a session — the matching entry lights up automatically. You don’t select a sim manually; onRails detects whichever one is running.

Supported sims: Assetto Corsa, Assetto Corsa Competizione, Automobilista 2, iRacing, Le Mans Ultimate, Project CARS 2, rFactor 2.

rFactor 2 needs one extra step. Because rF2 has no built-in telemetry API, onRails ships a small plugin (rF2_onRails.dll) that you drop into your rF2 plugins folder. Click the ? button next to the sim strip for the exact install steps — it’s a one-time, two-minute setup.

Le Mans Ultimate note: LMU uses Num 2 and Num 4 for in-cockpit seat adjustment, which overlaps two of onRails’ default hotkeys (see below). If LMU is your active sim, you’ll see a small warning icon next to its name — hover it for details on rebinding.

If nothing lights up, double check your sim is actually loaded into a driving session (not just the main menu) — most readers need you on track before they report data.

The two cards on the Launcher are separate tools for separate jobs:

onRails can run as a transparent overlay on top of your sim, or as a solid window you alt-tab to. Toggle this from the status indicator in the top-left corner of the screen (click the dot + “OVERLAY ENABLED/DISABLED” text). Click the ? next to it for a plain-language explanation of what transparent mode does.

Your sim needs to be in borderless windowed mode for the overlay to work. A true fullscreen (exclusive fullscreen) game takes over the entire display and won’t let onRails draw on top of it — you’ll either see nothing or the overlay will flicker behind your sim. Switch your sim’s display mode to borderless (or “windowed fullscreen”) in its own video settings before turning the overlay on.

The Launcher itself always opens as a normal window — the overlay toggle only takes effect once you enter SDT or the Setup Engineer.

The ••• button in the top-right corner of the Launcher opens a dropdown with everything else you need:

• Display — on a multi-monitor setup, pick which monitor onRails opens on. Useful if your sim runs on one screen and you want onRails on another.
• Language — opens a submenu of every supported language (see below). onRails auto-detects your OS language on first launch, so you shouldn’t need this unless you want to override it.
• Send Feedback — opens a direct line to report bugs or suggest features.
• Changelog — shows what’s changed release to release.
• Version number — at the bottom, so you know exactly what build you’re running when reporting an issue.

onRails auto-detects your system language on first launch. To change it manually, open the ••• menu → Language and pick from the submenu. Currently supported:

• English
• Español (Latinoamérica)
• Español (España)
• Português (Brasil)
• Português (Portugal)
• Deutsch
• Français
• Italiano
• Polski
• Čeština
• Türkçe
• Русский

Changing it applies immediately across the whole app, no restart needed.

Open Settings from inside either module (not from the Launcher — settings live one level in). A few things worth knowing on first visit:

• Transparency slider — controls how see-through the overlay is, separate from the on/off toggle above.
• Font size — four steps, useful if you’re running a high-DPI monitor or sitting far from the screen.
• Accent color — four color themes for the UI (default is McLaren orange).
• Card-Style Recommendations — toggles whether setup advice shows as a one-at-a-time card carousel (default) or a scrollable list of tiles. Personal preference, no functional difference.

Each screen has small “i” buttons next to anything that needs explaining — the sim strip, the overlay toggle, and per-sim setup requirements all have one. If you’re stuck beyond that, check the setup guides strip on the Launcher for written walkthroughs, or reach out through the Discord/Facebook icons in the top-right corner.