Written by Muneeb Rana · Last updated 26 October 2026
Quick answer: How to use HUD mode: open the speedometer app, switch on HUD (mirror) mode before you drive, and lay the phone flat on the dashboard below the windscreen. The mirrored digits reflect off the glass so they read correctly from the driver's seat. It works best at night; in daylight the reflection is faint. Set everything up while parked.
TL;DR
- Turn on HUD mode while parked.
- Lay the phone flat, screen up, under the glass.
- Max brightness; works best at night.
- Use a non-slip mat.
- Never adjust while moving.
How to use HUD mode in Speedometer PRO
Open the Speed tab, tap the HUD control to mirror the display, then place the phone on the dashboard. The display flips horizontally so the reflection reads normally. See HUD mode feature.
Placement
Put the phone directly ahead of the driver, near the base of the windscreen, on a non-slip pad. Make sure it cannot slide into the footwell under braking and does not block your view of the road. Check local rules on dashboard mounting.
Brightness and glare
Turn brightness up and let the phone stay awake. On many windscreens you will see a double image because the glass has two surfaces; a HUD reflective film reduces this. Daylight washes out reflections, so many drivers use HUD at dusk and night and the normal view by day.
Heat and battery
Phones lying in sun on a dashboard can overheat. Keep it shaded when parked, use a charger on long trips, and see GPS battery drain.
Troubleshooting
| Problem | Fix |
|---|---|
| Digits read backwards | HUD mirror is off; switch it on |
| Reflection too faint | Raise brightness, drive at dusk, add HUD film |
| Double image | Add HUD film or shift the phone slightly |
| Speed shows 0 | GPS lost; see app not working guide |
Cleaning the glass
A clean windscreen gives a sharper reflection. Clean the inside of the glass regularly.
Safety
HUD mode is meant to reduce how far you look away, not to invite interaction. Do not tap the phone while moving. If a reading looks wrong, pull over first. See what is a HUD.
Related: HUD speedometer guide · Speedometer HUD mode for your windshield · What is a HUD? · HUD display for car: your options · Phone mount placement: where to put your phone · GPS battery drain: how to reduce it · All speedometer guides · GPS speedometer guide
Get Speedometer PRO on Google Play · Download on the App Store · Set it up before you move; never handle your phone while driving.
Sources
- Head-up display (Wikipedia): en.wikipedia.org (accessed 26 October 2026)
- Distracted Driving (NHTSA): nhtsa.gov (accessed 26 October 2026)
- Speedometer PRO・MPH Tracker (Google Play listing): play.google.com (accessed 26 October 2026)
- Speedometer PRO・MPH Tracker (App Store listing): apps.apple.com (accessed 26 October 2026)
FAQ
Does HUD mode work in daylight?
It can, but reflections are faint in bright sun. It is clearest at dusk and night.
Why are there two images on my windscreen?
Windscreen glass has inner and outer surfaces, each reflecting. A HUD film or windscreens designed for HUD reduce the ghosting.
Is HUD mode free in Speedometer PRO?
. Check the app's Premium screen for current details.
Is a phone on the dashboard legal?
Rules vary by country and state. Many limit where devices can sit or how they may be used. Check your local law.
Will it drain my battery?
A bright screen plus GPS uses noticeable power. Keep the phone charging on long drives.