Does Your Dash Cam Record Speed? How to Use It (and Hide It) Correctly

You've just set up your dash cam and you're wondering: does this thing actually record my speed? And if it does, could that footage be used against you one day?

Good questions. Most modern dash cams do record speed, and that data can work for you or against you depending on how you have set it up. Here's what every Australian driver needs to know.

Do Dash Cams Record Speed, and How Does It Work?

Dash cams with GPS track your speed, but not by plugging into your car's speedometer. Instead, they use a built-in GPS antenna to calculate speed by measuring the time it takes to travel between two GPS coordinates.

This is actually more accurate than your car's speedo. Manufacturers are legally required to calibrate speedometers to read at or slightly above your actual speed, so your dash might show 105 km/h when you are doing 100. A GPS-enabled dash cam shows the real number.

For GPS to work properly, the camera needs a clear signal from at least four satellites. In tunnels or dense city streets, the signal can drop out briefly, causing the speed reading to lag or disappear for a moment.

Is Your Speed Visible on the Video?

This is where it gets interesting. Most GPS-capable dash cams display a "speed stamp" on the video overlay. You have probably seen footage online with the speed, date, and time burned into the bottom corner of the frame. That is the speed stamp.

Pro Tip: Most quality dash cams let you keep GPS recording active (for accurate timestamps and location data) while turning the speed stamp off so it does not appear on the video itself. This keeps your footage clean and gives you more control over what anyone watching can immediately see.

Could Your Speed Data Be Used Against You?

Honest answer: it depends.

GPS speed data from a dash cam will not get you a speeding fine. Australian police use certified radar or lidar equipment for that. But in civil insurance disputes, your speed data absolutely can be used as evidence.

If you were 5 km/h over the limit at the moment of an incident, an insurance assessor could use that to assign partial fault to you. On the other hand, if you were travelling within the speed limit and another driver was at fault, that same GPS data becomes strong proof in your favour.

This is why we recommend turning the speed stamp off on the video overlay rather than disabling GPS entirely. The speed data is still recorded in the file's metadata, where a lawyer or insurer can extract it if needed, but it is not visible to anyone who simply plays the video.

What Makes Dash Cam Speed Recording More Accurate?

Not all GPS is equal. Budget cameras often update their position once per second, which is called 1 Hz. That sounds frequent, but at 100 km/h your car covers about 28 metres between updates. In a short incident, those gaps can matter.

Premium dash cams use GPS that refreshes at 5 Hz or 10 Hz, meaning five to ten position updates per second. That gives you a much smoother and more accurate speed log. If reliable speed evidence matters to you, this is worth checking before you buy.

Brands like Vantrue use high-refresh GPS as standard on their front and rear camera systems, which is one reason they are popular with Australian drivers who spend a lot of time on the highway.

Can Police Seize Your Dash Cam for the Speed Data?

Yes. In serious incidents, Australian police have the power to seize electronic devices. If your speed is visible as a stamp on the video, it is immediately readable by anyone who opens the file. That is another good reason to leave GPS active while turning the stamp off.

Frequently Asked Questions

Is dash cam speed accurate enough for court?

It is rarely accepted as sole evidence to issue a fine against another driver, but it is highly effective in civil insurance disputes to prove you were travelling within the speed limit or reacting to a hazard within a reasonable time.

Which setting should I use?

For most Australian drivers, the best approach is to keep GPS active and turn the speed stamp off on the video overlay. Your speed data is preserved in the file's metadata for anyone who needs it, but it is not on screen by default.

If you drive frequently through tunnels or underground car parks where GPS drops out, you can disable GPS entirely without affecting video recording. You will just lose speed and location data for those sections.

Need Help Choosing the Right Dash Cam?

Have a look at our full range of GPS-enabled dash cams, or reach out to Michael or Harrison directly. We are happy to walk through what your situation calls for. Send us an email at gday@dashcamguys.com.au or give us a ring on 1800 CAM GUY. No worries at all.