We’ve had a few questions from timers and race organizers about how much mobile data is used when uploading photos through RunSignup’s RaceDay Mobile Timing App. When capturing and uploading hundreds of participant photos, especially over a cellular connection, even small file sizes can add up. This blog explains how photo quality and compression settings affect data usage — and how you can adjust them to better manage your data plan and upload process.
📸 Photo File Size by Device, Quality & Compression
Photo sizes vary significantly based on the combination of photo resolution (MP) and compression level. Below are measured averages for iOS and Android devices.
iOS Devices
| Compression Level | High Quality (9MP) | Medium Quality (5MP) | Low Quality (2MP) |
|---|---|---|---|
| High Compression | 0.18 MB | 0.11 MB | 0.05 MB |
| Medium Compression | 0.55 MB | 0.26 MB | 0.12 MB |
| Low Compression | 6.04 MB | 3.62 MB | 1.74 MB |
Android Devices
| Compression Level | High Quality (9MP) | Medium Quality (5MP) | Low Quality (2MP) |
|---|---|---|---|
| High Compression | 0.07 MB | 0.04 MB | 0.02 MB |
| Medium Compression | 0.50 MB | 0.32 MB | 0.16 MB |
| Low Compression | 5.11 MB | 3.26 MB | 1.52 MB |
💡 Note: Portrait vs. Landscape mode does not affect the file size — the resolution (number of pixels) is the same.
📶 How Much Data Does the Mobile Timing App Photo Upload Feature Use?
Let’s break it down:
- With the Mobile Timing App’s default settings (High Quality, Medium Compression), a typical photo may be around 0.5 MB per image.
- Uploading 250 photos would consume approximately 125 MB of data.
That 125 MB would be counted against your mobile data plan, assuming the upload occurs over cellular. There’s no hidden overhead or compression applied by the app beyond what’s configured in the settings.
🔧 Managing Data Usage in the RaceDay Mobile Timing App
By default, the RaceDay Mobile App is configured to allow photo uploads over cellular. However, this and the default Image settings can be modified:
- Toggle to Wi-Fi Only: Prevent uploads on cellular to conserve data.
- Adjust Photo Quality & Compression: Lower quality or increase compression to significantly reduce file sizes. For example, moving from Low Compression (5MB per photo) to High Compression (under 0.1MB) can yield 50x savings.
📊 Real-World Scenario Comparison
| Scenario | Est. File Size per Photo | Total for 250 Photos | Notes |
|---|---|---|---|
| Default (High Q, Medium C) | ~0.5 MB | ~125 MB | Common use case |
| High Q, Low Compression | ~5 MB | ~1.25 GB | Drains data quickly |
| Low Q, High Compression | ~0.05 MB | ~12.5 MB | Most data-efficient setting |
🧠 Tips for Timers and Race Directors
- Plan Ahead: If you’re expecting high volumes of photo uploads, consider pre-setting devices to use Wi-Fi only or switch to high compression mode.
- Use Wi-Fi: Delay uploads until you’re connected to a Wi-Fi hotspot, especially when data limits are a concern.
- Test Before Race Day: Use a sample batch of photos to determine actual sizes and test upload speeds on your available networks. If you’re considering using the Low Quality setting, testing becomes especially important. While this option significantly reduces file sizes and saves data, the resulting image clarity may not meet your expectations — or those of your participants. Try capturing a few photos using the Low Quality setting to make sure they still provide the level of detail and recognition you want for race results and photo sharing.
Check Actual Data Usage on Your Device
Both Apple and Android devices allow you to review data usage by individual apps, which can be helpful when evaluating how much data the RaceDay Mobile Timing App is consuming during photo uploads.
On Apple Devices (iPhone/iPad):
- Open Settings
- Tap Cellular
- Scroll down to Cellular Data section
- Review data usage under “RaceDay Mobile Timing” (or the app name listed)
This will show the amount of cellular data used by each app since the last reset of usage stats.
On Android Devices (Samsung, Pixel, etc.):
- Open Settings
- Tap Connections or Network & Internet
- Select Data Usage
- Tap Mobile Data Usage
- Locate and tap the RaceDay Mobile Timing app to see detailed usage
Tip: You can reset your statistics before testing to isolate the data usage from just your trial session.
By reviewing these metrics, you’ll get a clearer picture of how different settings impact your actual data consumption in real-world conditions.
About RaceDay Mobile Timing App
The RaceDay Mobile Timing App is a free tool developed by RunSignup to support backup timing, small event timing, and contingency planning for larger chip-timed races. The app works in conjunction with RunSignup’s results platform for real-time results publication.
In addition, timers can take advantage of the real-time photo capture integration, allowing race timers to capture and auto-tag participant photos directly from the app. Images are instantly linked to participants’ results pages and the event’s photo gallery.
Download the RaceDay Mobile Timing App
The free RaceDay Mobile Timing app is available to use with iOS or Android devices:
Download from Google Play Store
