What is the best free GPS overlay tool for track day videos?

For basic speed, map, and elevation: Stamptivity Overlay (free, browser-based, GPX/FIT input). For OBD-II engine data and G-force with motorsport gauges: RaceRender's free tier (adds a watermark on export). The best choice depends on whether you need OBD-II data or are fine with GPS-only data from a watch or phone.

What data can I overlay on motorsport videos?

With GPS only (from a watch or phone app): speed, map, elevation. With OBD-II: speed, RPM, throttle position, brake pressure, engine temperature. With a dedicated track logger (AiM, Race Technology): all of the above plus G-force, steering angle, sector splits, lap time.

Can I use Stamptivity for motorsport videos?

Stamptivity Overlay works well for basic speed and GPS map overlays on track day videos if you have a GPX or FIT file from a GPS watch or phone. It does not support OBD-II data, G-force, or lap timing. For those features, RaceRender or Harry's LapTimer are the dedicated tools.

Does RaceRender work on Mac?

No. RaceRender is Windows-only. For Mac users, Stamptivity Overlay (browser-based) handles GPS speed overlays. For full motorsport telemetry on Mac, Telemetry Overlay (paid) supports OBD-II via some adapters.

How do I record GPS data for a track day overlay?

Options: wear a GPS watch (Garmin, Coros, Apple Watch) and start a GPS activity before going on track. Use a phone with a track day app (TrackAddict, Harry's LapTimer). Use a dedicated track data logger (AiM Solo 2, Race Technology RT4). The first option is the lowest cost and works with any car.

GPS Telemetry Overlay for Track Day & Motorsport Videos

Track day videos are more interesting with data. Not just fast-looking corners — the actual speed through that chicane, the G-force on the braking zone, the lap time improving run by run. The tools to produce this range from free browser apps to professional-grade motorsport software depending on how deep you want to go.

This guide covers the options for adding GPS telemetry overlay to motorsport and track day videos, from simple setup to full data logging.

Data Sources for Motorsport Overlay

Before choosing a tool, decide what data you can record:

Option 1: GPS Watch or Phone (Simplest)

Wear a GPS watch (Garmin, Coros, Apple Watch) during your track session and start a GPS activity. Works with any car, no wiring, no install. After the session, export the GPX or FIT file.

Data available: Speed, GPS coordinates, elevation, heart rate (if HRM connected)

Not available: RPM, throttle, G-force, lap time

Best for: Casual track day drivers who want a speed gauge overlay without complex setup.

Option 2: Dedicated Track App on Phone

Apps like TrackAddict (iOS/Android), Harry's LapTimer (iOS), or Racechrono (Android/iOS) use phone GPS and can connect to OBD-II adapters for engine data. They also handle lap timing based on a known track map.

Data available: Speed, GPS, lap time, sector splits, OBD-II (with adapter)

Best for: Regular track day drivers who want lap timing without dedicated hardware.

Option 3: Dedicated Data Logger (Professional)

Hardware units like AiM Solo 2, Race Technology RT4, or Starlane GPS mount in the car and log GPS at high frequency (5–10Hz), G-force, and optionally OBD-II. More accurate at track speeds than phone GPS.

Data available: High-accuracy speed, G-force, steering angle, all OBD-II channels, lap time, sector splits

Best for: Club racing, time attack, or serious track day enthusiasts.

Tool Comparison for Motorsport Overlay

Stamptivity Overlay — Free, Any OS, GPS-Only

stamptivity.app/overlay — works with GPS watch or phone GPX/FIT

Best for: Track day drivers who carry a GPS watch and want a simple speed + map overlay without any software install. No OBD-II or G-force support.

Load the GPX from your Garmin or phone, open the browser tool, add a speed gauge and map. Done in 10 minutes.

RaceRender — Best Free Option for Full Motorsport Data

Windows · Free tier (watermark) · Paid ~$40 (no watermark)

RaceRender is the most widely used free-to-affordable motorsport overlay tool. It handles GPS data from any source, OBD-II via a compatible ELM327 adapter, and G-force from a compatible phone or logger.

Key features:

Motorsport-specific gauge library (tachometer, G-meter, speed dial, lap delta)
Sector splits and lap time overlay
OBD-II channel support
Works with multiple simultaneous cameras (split-screen)

Limitations: Windows only; free tier adds a watermark.

Harry's LapTimer — Best iOS Option

iOS · ~$12–$40 depending on tier

Records GPS and OBD-II data from your iPhone while you're on track, then syncs it with video recorded simultaneously. Built specifically for lap timing. Best for iPhone users who want a self-contained solution.

Telemetry Overlay — Best Mac Option for Motorsport

~$40 one-time · Windows + macOS

Originally designed for GoPro GPMF sports data, Telemetry Overlay has expanded to support OBD-II data via some adapters. Works on Mac — the main advantage over RaceRender for Mac users. Active development.

AiM Race Studio — Professional Grade

Free software (requires AiM hardware) · Windows + macOS

If you have AiM hardware (Solo 2, MXS dash, or similar), Race Studio 3 is the professional overlay software for the logged data. Extremely detailed telemetry, multi-channel comparison, professional-quality output. Not relevant without AiM hardware.

Comparison Table

Tool	Price	Platform	GPS	OBD-II	G-force	Lap time	Watermark
Stamptivity Overlay	Free	Browser	✓	✗	✗	✗	None
RaceRender Free	Free	Windows	✓	✓	✓	✓	Yes
RaceRender Paid	~$40	Windows	✓	✓	✓	✓	None
Harry's LapTimer	~$12–40	iOS	✓	✓	✓	✓	None
Telemetry Overlay	~$40	Win + Mac	✓	Limited	✓	✗	None
AiM Race Studio	Free (AiM hardware)	Win + Mac	✓	✓	✓	✓	None

Which Setup for Which Driver?

Occasional track day, any OS, minimal setup → GPS watch → GPX → Stamptivity Overlay. Speed and map, zero investment.

Frequent track days, Windows, want OBD-II data → RaceRender paid + OBD-II ELM327 adapter. Full data, clean output.

iPhone user who wants lap timing → Harry's LapTimer.

Mac user who wants motorsport-grade output → Telemetry Overlay (best Mac option with OBD-II support).

Club racing or time attack with serious data logging → AiM Solo 2 + Race Studio 3.

Tips for Better Track Day Overlays

Camera placement: Dash cam style (windscreen-mounted) is the standard for track day content. Helmet cam gives a more immersive perspective. Both work — the GPS overlay provides the context regardless of angle.

Synchronising GPS to video: For a GPS watch recording, the sync method is finding a clear event — the pitlane exit, the formation lap starting, entering turn 1. Drag the offset until speed matches the video. Most syncs take under 2 minutes.

Speed units for track content: Set your speed gauge to km/h for international audiences; mph if your content is US-focused. Motorsport audiences generally understand both.