When your recorded walking or running route looks like a series of straight lines or sharp zig‑zags, it usually means your phone temporarily lost an accurate GPS fix. The app connects the last known points with straight segments, so gaps or large jumps show up as broken or jagged lines.  Understanding what interferes with GPS and how to improve your phone’s signal will make your routes much smoother.

Why does this happen?

Modern phones combine signals from satellites, mobile towers, Wi‑Fi and Bluetooth to estimate location.  Several factors can degrade that estimate and cause erratic route lines:

• Signal interference or physical obstructions – Your phone must “see” at least four satellites to determine its position.  Tall buildings, dense forests and even thick clouds can block or bounce those signals.  GPS works best in open areas. 
• Poor hardware or phone settings – Cheaper phones may have lower‑quality GPS chips , and low‑power modes can intentionally reduce GPS accuracy to save battery.  Incorrect location permissions or disabled Wi‑Fi/Bluetooth scanning also affect accuracy. 
• Software and map issues – Bugs in apps or outdated map data can produce wrong coordinates.  Multiple apps using GPS at the same time can interfere with each other.

General best practices

1. Start with a strong signal 

   Before you tap “Start,” open Pacer outdoors and wait for the location dot to stabilize.  GPS accuracy improves dramatically when your phone has an unobstructed view of the sky.  Avoid urban “canyons” created by tall buildings , dense tree cover, tunnels or heavy rain. 

2. Keep the phone steady 

   Secure the phone in an armband, belt or pocket so it doesn’t bounce around.  Random movements can make some devices think you’re jumping between locations. 

3. Stay up to date 

   Update Pacer and your phone’s operating system to the latest versions.  Manufacturers fix GPS bugs in updates, and newer location APIs often improve precision. 

4. Turn off battery‑saving modes while tracking 

   Low‑power modes and app “sleep” features can disable sensors or reduce the frequency of GPS updates.  Disable battery savers or whitelist Pacer so it can run in the background.

iOS‑specific steps

• Check location permissions 

  Go to Settings → Privacy & Security → Location Services → Pacer and set it to Always or While Using the App.  If you deny precise location, iOS may only provide approximate data. 

• Enable Motion & Fitness access 

  In Settings → Privacy & Security → Motion & Fitness, ensure Pacer is turned on.  This lets Pacer combine motion sensor data with GPS for better smoothing. 

• Allow Background App Refresh 

  Enable Settings → General → Background App Refresh for Pacer so the app stays active during your activity. 

• Disable Low Power Mode 

  When your phone enters Low Power Mode, GPS and background activity may be limited.  Turn it off under Settings → Battery before recording long workouts.

Android‑specific steps

• Use High‑accuracy location mode 

  Go to Settings → Location (or Location Services) and select High accuracy (this may be labelled Google Location Accuracy).  High‑accuracy mode combines GPS, Wi‑Fi and mobile networks to improve positioning.  Enabling Google Location Accuracy, Wi‑Fi scanning and Bluetooth scanning lets apps use nearby Wi‑Fi and Bluetooth signals for more precise location. 

• Restart GPS and move outdoors 

  If you start indoors and see jagged lines, step outside and toggle your phone’s location icon off and on to re‑activate GPS. 

• Check app permissions 

  From Settings → Location → App Permissions, select Pacer and choose Allow all the time.  Without continuous permission, Android may only deliver approximate location or pause updates when the app is in the background. 

• Disable battery optimization 

  In Settings → Battery (or App Power Management), find Pacer and set it to Unrestricted or Don’t optimize.  On some brands (Samsung, Xiaomi, Huawei, Oppo, etc.) there are extra “sleeping apps” or “auto‑start” lists—ensure Pacer is excluded so it can keep recording even when the screen is off. 

• Keep Wi‑Fi and Bluetooth on 

  Even if you’re not connected, leaving Wi‑Fi and Bluetooth turned on allows assisted‑GPS features to use nearby signals for better accuracy.

Still seeing jagged lines?

• Wait for the route to settle – If the first minute of your walk shows a zig‑zagging line, give your phone time to adjust.  Once the GPS locks on, the rest of the route should smooth out. 
• Check for hardware limitations – Older or budget devices may have weak GPS antennas and slow processors.  In areas with poor reception, even newer phones can struggle. 
• Compare with other apps – Try recording a short route with another mapping app.  If both show similar jumps, the problem is likely signal‑related.  If only Pacer shows issues, contact our support team through Pacer → Settings → Help & Support. 

With the right settings and a clear view of the sky, your GPS route should draw smooth lines rather than broken segments.  Follow the steps above to optimize your device and enjoy more accurate activity tracking.