See where you lose time in iRacing.

TwinMetric is a free iRacing telemetry analyzer for Windows. It compares saved laps from .ibt files on any track and car: time delta, speed, pedals, track map, sectors and corner hints. It works offline, with no account.

Download for Windows version 0.2.2, zip 6.5 MB See how it works

Example Circuit de Spa-Francorchamps (Grand Prix) · FIA F4 · real laps

ComparisonR: 4 (21-43-31) · 2:23.624P1: 2 (21-35-03) · 2:23.959

Track map2:23.624

Delta [s]

Speed [km/h]

Throttle [%]

Brake [%]

Three laps in one window

The window has the lap list on the left, seven charts in the middle and the track map with sectors and corners on the right. The screenshots show an example session at Spa-Francorchamps in the FIA F4, from two .ibt files.

TwinMetric window, dark theme: lap list, seven telemetry charts, track map, sector table and corner hints (Spa-Francorchamps, FIA F4). — Screenshot, dark theme: Spa-Francorchamps in the FIA F4. Reference lap R (blue) and two compared laps, P1 (orange) and P2 (green), all from one session.

TwinMetric in the light theme, zoomed in on corner 9 at Spa: cursor at 6712 m, delta +0.391 and −0.324 s, speeds 82.8, 86.0 and 84.4 km/h. — Screenshot, light theme: corner 9 (numbered by the app), the Bus Stop chicane before the line at Spa, zoomed in.

A corner, zoomed in

Readout under the cursor: Next to each chart title you see the value of every lap at the cursor position. Here, at 6712 m, the delta reads +0.391 and −0.324 s, and the speeds are 82.8, 86.0 and 84.4 km/h. P1 is in second gear, P2 in first.
Zooming: Drag across a chart to zoom all charts to that stretch. Pan with the right mouse button and zoom with Ctrl and the mouse wheel. A double click brings back the whole lap.
The map and the charts stay in sync: After you zoom the charts, the map shows the same stretch of track and the dots mark where each lap is. Zoom the map with the mouse wheel or drag it, and the charts follow.

Lap comparison features

Any iRacing track, any car

The app needs no track data in advance: it reads everything from the .ibt recording. You have nothing to set up per track or per car, and a new track or car is one more file in your telemetry folder.

You can only compare full laps from the same track, layout and track version.

Track, layout, length, car: from the .ibt file header
Sectors: from the sector split that iRacing writes into the file
Track map: from the car position stored in the recording
Corners: the app detects them from speed drops

Seven charts on one distance axis

Time delta, speed, throttle, brake, gear, RPM and steering sit one above another on a shared distance axis, in metres from the start line. A given spot on the track lines up on all seven charts. A climbing delta line means you are losing time to the reference. The charts below it show how speed, throttle and brake differed on that stretch.

You pick one reference lap (R) and up to three laps to compare (P1, P2, P3). Until you choose, the reference is your personal best at that track in that car.

Delta [s]
Speed [km/h]
Throttle [%]
Brake [%]
Gear
RPM [rpm]
Steering [°]
axis: distance [m]

Track map

The map shows the driving line of every lap from above, with corner numbers and a dot for each lap at the cursor. The app builds it from the car position stored in the recording, so you get a map of any track without extra data. Zoom the charts and the map shows the same stretch of track. It works the other way round too: the mouse wheel zooms the map to the stretch you point at, dragging pans it, and the charts follow. Zoom all the way out or double-click to return to the whole track and the whole lap.

Sectors and the theoretical lap

You see the time of each sector and the gap to the reference. The “theor.” row adds up the best sectors of the selected laps and shows which lap each one comes from. The example below uses one session at Spa-Francorchamps (FIA F4) and the same laps as the animation at the top of the page:

Sector times of laps R and P1 (example: Spa-Francorchamps, FIA F4) and the theoretical lap
lap	S1	S2	S3	S4	total
R	0:42.452	0:33.439	0:29.024	0:38.710	2:23.624
P1	0:42.481+0.030	0:33.910+0.471	0:29.027+0.004	0:38.540−0.170	2:23.959+0.335
theor.	0:42.452(R)	0:33.439(R)	0:29.024(R)	0:38.540(P1)	2:23.454

Corners with hints

The app finds corners from speed drops and numbers them from the start line, so the numbers are its own: in this F4 session at Spa it found 9 corners, while iRacing lists 19 turns. For each compared lap it shows how the lap differs from the reference in braking point, minimum speed and full-throttle point, skipping differences under 5 m (braking, full throttle) and under 2 km/h (speed). A hint describes the difference without judging it: the time in the corner tells you whether it helped. Example from the same session (P1 against R; corner 3 is Les Combes, corner 4 is Bruxelles):

corner 3+0.275 sbraking 16 m earlier, min speed -7 km/h, full throttle 6 m later
corner 4+0.173 sfull throttle 16 m earlier
corner 8−0.211 smin speed +3 km/h, full throttle 8 m earlier

New recordings load automatically

The app watches the Documents\iRacing\telemetry folder and loads every new .ibt file, even while you drive. It rereads a file whenever iRacing appends to it. You can also drag files onto the window or use “Open with”.

Loading the same file again, or a copy of it, adds no duplicate laps. Removing a session from the library deletes nothing from disk: the app puts the recording on an exclusion list, and you can bring it back at any time.

Works offline

The app needs no internet connection or account and sends nothing anywhere. It only reads your .ibt files and never changes or deletes them.

English or Polish, km/h and metres

The window starts in English; Polish is one click away (the EN | PL switch on the toolbar or the “Language:” row in the settings), and the choice is remembered. Speeds are in km/h and distances in metres, and you can pick a light, dark or system theme.

`ibt.exe` for power users

The zip also includes a command-line version with the commands info, channels, laps, dump, compare, export (CSV or JSON), library and watch, each with JSON output. It writes in English; set the environment variable IBT_LANG=pl for Polish messages. The JSON keys and the CSV column names do not change with the language, and the CSV columns have Polish names, for example dystans_m and predkosc_kmh.

How to compare iRacing laps

Download and unzip

Right-click the zip, choose “Extract All…” and run iracing-telemetry.exe from the extracted folder. There is no installer, and you can keep the app in any folder.
Record telemetry in iRacing

In iRacing, press Alt+L. A telemetry icon appears on screen, and every time you get into the car, iRacing starts a new .ibt file in Documents\iRacing\telemetry. Drive a few full laps.
Compare laps

The app picks up the new files. In the list, mark the reference (radio button) and the laps to compare (checkboxes), then read the charts: you are losing time wherever the delta line climbs.

Free download for Windows

TwinMetric 0.2.2 for Windows 10 and 11 (64-bit) comes as one zip, with no installer and no sign-up.

Download for Windows TwinMetric-0.2.2-windows-x86_64.zip, 6.5 MB

SHA-256 of the zip

280D66397EAC62B86BC6080B5C27BC9EC26D3B77A37D3250F5B043B58275DBD6

Checksum file: SHA256SUMS.txt

Version: 0.2.2, released 22 October 2026.
Previous name: TwinMetric used to be called K4 Analizer. Data from the earlier version stays: the folder %LOCALAPPDATA%\IracingTelemetry has not changed.
In the zip: iracing-telemetry.exe (the app), ibt.exe (command line), README.md (the full guide), README.pl.md (its Polish version) and a docs folder with images.
Updating from 0.2.x: Unzip the new version (you can delete the old program folder). Your lap library and settings stay, because they live outside the program folder (see “App data”). Compared with 0.2.1, version 0.2.2 changes only the name and icon; the features are the same. If you are updating from 0.2.0: since 0.2.1 the window starts in English by default, and you switch the language with EN | PL on the toolbar or the “Language:” row in the settings.
Requirements: Windows 10 or 11, 64-bit, and a working graphics driver (the app draws its window with OpenGL); if iRacing runs on this PC, you already have one. You need no extra packages or libraries.
Installation: None. Extract the whole zip (do not run the app from inside it) and double-click iracing-telemetry.exe. To remove the app, delete the folder.
SmartScreen: This page is the only official source of the zip. The app is not signed with a publisher certificate, so Windows may show “Windows protected your PC” on first launch. Check your download against the SHA-256 checksum next to the button, then click “More info” and “Run anyway”.
App data: The app saves laps, settings and the window position in %LOCALAPPDATA%\IracingTelemetry. Your .ibt files stay where iRacing saved them.

Is it safe?

What it does: it reads the .ibt files in your iRacing telemetry folder and keeps its own lap library in %LOCALAPPDATA%\IracingTelemetry. It never changes or deletes your .ibt files.
What it does not do: it needs no account and no internet connection, and it sends nothing anywhere.
Why Windows warns you: the app is not signed with a publisher certificate, so SmartScreen does not know it. Click “More info”, then “Run anyway”, but only after the check below.
Check your download: this page is the only official source of the zip. In PowerShell, in the folder with the zip, run Get-FileHash .\TwinMetric-*.zip -Algorithm SHA256 and compare the result with the checksum above (it is also in SHA256SUMS.txt). If the checksums differ, delete the file.
Questions and problems: [email protected].

FAQ: TwinMetric and iRacing telemetry

What is TwinMetric?

TwinMetric is a free Windows 10 and 11 (64-bit) program that compares laps from iRacing telemetry. It reads the .ibt files iRacing saves on your disk and shows time delta, speed, throttle, brake, gear, RPM, steering, a track map, sectors and corner hints for a reference lap and up to three other laps. It works offline and sends nothing anywhere.

Is TwinMetric free?

TwinMetric is free to download and use, and it needs no account.

Is TwinMetric safe?

TwinMetric works offline, sends nothing and only reads your .ibt files: it never changes or deletes them. The app is not signed with a publisher certificate, so Windows SmartScreen may warn on the first launch. This page is the only official source of the zip. Before you run it, compare your download with the SHA-256 checksum: the steps are under “Is it safe?” in the download section.

Why does Windows warn me on launch?

The app is not signed with a publisher certificate (a paid service this free project does not use), so SmartScreen does not know its author and warns you as it would for any such program downloaded from the internet. Get the zip only from this page and check it against the SHA-256 checksum next to the download button (Get-FileHash .\TwinMetric-*.zip -Algorithm SHA256 in PowerShell). Then click “More info” and “Run anyway”. If your antivirus blocks or quarantines the file, do not switch off the protection or add an exception for it. New unsigned programs are sometimes flagged by mistake, but if the checksum does not match or you are not sure, do not run the file.

Is TwinMetric an official iRacing tool?

No, TwinMetric is an independent project, not affiliated with or endorsed by iRacing.com Motorsport Simulations or Garage 61; the names iRacing and Garage 61 belong to their owners. The app only reads the telemetry files that iRacing saves on your own PC and does not use your iRacing account.

Does it work with ACC, Le Mans Ultimate, Assetto Corsa or other sims?

No, TwinMetric works with iRacing only for now: release 0.2.2 reads just the .ibt telemetry files that iRacing writes and cannot open recordings from other simulators.

Does TwinMetric analyse corners and sectors?

TwinMetric finds the corners itself, from clear drops in speed on the reference lap, and numbers them from the start line. For each compared lap it shows the time lost or gained in every corner and a hint in plain words, for example “braking 8 m later, min speed -3 km/h”: where braking starts, the minimum speed and where full throttle comes, compared with the reference. The sector table splits the lap into the same sectors as iRacing and shows each sector time with the difference to the reference. Its “theor.” row takes the best time of each sector among the selected laps, shows which lap it comes from and adds them up into a theoretical lap.

What is an .ibt file and how do I open it?

An .ibt file is iRacing’s own telemetry recording. With recording on (Alt+L), iRacing starts a new file every time you get into the car and saves it in Documents\iRacing\telemetry. The file holds the car’s data sample by sample: speed, throttle, brake, gear, RPM, steering, position on track and more. Windows has no viewer for it: drag the file onto the TwinMetric window or use “Open with”, and files from the telemetry folder load on their own.

How do I turn on telemetry recording in iRacing?

Press Alt+L in iRacing (it also works outside the car). A telemetry icon appears on screen and lights up once you are in the car. iRacing saves the files in Documents\iRacing\telemetry and creates that folder with the first recording. Press Alt+L again to turn recording off.

Does it work with any track and car?

TwinMetric works with any iRacing track and car. It reads the track, layout, length, car and sector split from the .ibt recording, draws the map from the car position stored in it and finds corners from speed drops, so you have nothing to set up for a particular track or car. You can only line up full laps from the same track, layout and track version, and until you pick another reference, the app uses your personal best at that track in that car. Spa-Francorchamps on this page is only an example from real recordings.

Is this live telemetry?

No, TwinMetric is not live telemetry. It analyses the .ibt files that iRacing writes to disk and compares saved laps. It loads new files even while you drive, but the charts show the recording, not the live session.

Does the app send my data anywhere?

TwinMetric sends no data anywhere. It works without internet or an account, only reads your .ibt files and never changes or deletes them. Your lap library stays on your disk, in %LOCALAPPDATA%\IracingTelemetry.

Do I need Garage 61 or an account?

TwinMetric does not need Garage 61, an iRacing login or any other account. It works on its own, offline, with the .ibt files on your disk, so there is no online lap library and no lap sharing.

Can I export iRacing telemetry to CSV or JSON?

You can export iRacing telemetry to CSV or JSON with ibt.exe from the zip. In PowerShell, in the app folder, .\ibt.exe export "session.ibt:2" --csv | Out-File -Encoding ascii lap.csv saves lap 2 of that file on a distance grid (every 2 m by default; change it with --step): distance, time, speed, throttle, brake, gear, RPM, steering and x/y position. Use --json instead of --csv for JSON. The CSV columns have Polish names, for example dystans_m and predkosc_kmh, in both languages.

Is the app in English?

TwinMetric is in English by default. The window starts in English, and you can switch it to Polish with the EN | PL switch on the toolbar or the “Language:” row in the settings; the choice is saved. Corner hints follow the window language. Speeds are in km/h and distances in metres.

Is there a macOS or Linux version?

TwinMetric is available for Windows 10 and 11 (64-bit); there is no ready-made macOS or Linux download. This is release 0.2.2.

What does this website store about me?

This website has no cookies, analytics or ads. It stores nothing in your browser. The app itself sends nothing: your .ibt files and lap library stay on your PC.