How offline caching works

Introduction

InfoBox screens are designed to keep playing even when the internet drops. Every paired Android device caches its content locally, so a network outage doesn't stop the slideshow. This article explains exactly how that works and what to expect.

What gets cached locally

On every device, locally:

• Every published media file the screen needs (images, videos, PDFs).
• The slide order and per-slide settings (duration, schedule, rotation, visibility).
• Power BI and iFrame URLs: cached as URLs but the actual content needs internet to reload at refresh time. iFrame slides display the last successful load when offline.
• YouTube videos: not cached locally. YouTube needs internet to play.

What plays during an outage

When the device loses internet:

• Image, video, PDF slides: keep playing as if nothing happened. The cache is the source.
• Power BI and iFrame slides: show the last successfully loaded view. Refresh attempts fail silently. Once internet returns, they refresh on the next scheduled refresh interval.
• YouTube slides: stop playing for the duration of the outage. The slide may show a black frame or skip to the next slide.
• Schedule and visibility logic: continues to work normally. Slides that should hide based on time still hide; scheduled appearances still appear.

What doesn't update during an outage

Things that need internet:

• Newly published content: queues on the server. The device picks it up when it reconnects.
• Resync requests: queued similarly.
• Device status reporting: shows Offline on the Platform until reconnected.

When internet returns

Recovery is automatic:

• The device detects connectivity and immediately reconnects to our servers.
• Status changes from Offline to Online on the Platform within ~1 minute.
• The device fetches any queued content updates.
• iFrame and Power BI slides resume their refresh schedules.
• No manual intervention is needed.

What about long outages?

Hours, days, or weeks offline:

• The device keeps playing the cached content indefinitely.
• Users see the same loop they last had before the outage.
• When connectivity returns, the device catches up on every queued change at once.
• There's no "go stale" failure mode. The screen keeps working until the device loses power or someone restarts it.

What doesn't survive a power loss

Cache survives reboot, but:

• The InfoBox Basic stick auto-launches the InfoBox Digital Signage app at boot. Cached content is on disk and resumes playing.
• Customer-supplied Android devices may not auto-launch the app at boot. If the device powers off, you may need to manually launch the app when it powers back on. See Setup: your own Android device for the auto-launch tip.
• If the device's local storage fills up (very rare with 8 GB+ devices), the cache may be partially purged. The next online sync re-downloads.

Summary

Cached files keep playing. Cached URLs (iFrame, Power BI) show their last load. YouTube needs internet. Recovery is automatic when internet returns. Power loss may require manual app launch on customer-supplied Android devices. The InfoBox Basic stick handles auto-launch automatically.