A Content Caching Guide for Appspace PWA Players

What Is Content Caching?

When the Appspace PWA Player displays content on a screen, it can save copies of that content directly on the device rather than downloading it from the internet every time. This is called caching.

Caching makes your screens more resilient — content continues playing even during brief network outages — and reduces how much bandwidth your network uses during normal playback.

Supported Caching PWA Devices

• Chromium browser (Windows/Mac/Linux)
• Cisco Webex
• Crestron AirMedia
• Google Meet
• Mersive
• Microsoft Teams Rooms (MTR)
• Poly
• Qbic
• Zoom Rooms on Android

Unsupported Caching PWA Devices

• Crestron AirMedia 200
• Crestron Mercury
• Zoom Rooms on Windows

What Gets Cached

Video Caching Rules

Videos are cached one at a time to prevent performance issues across the range of hardware the PWA Player supports. There is one hard file size requirement that applies to all PWA devices:

• Videos under 300 MB — cached normally
• Videos 300 MB or larger — always streamed from the internet; these are not cached regardless of available storage

Important: The 300 MB limit is a hard requirement, not a guideline. Any video file at or above this threshold will always stream on any PWA device.

There is no file size limit for individual images or cards — however, total channel content must fit within the device’s available cache storage. See the Device Storage section below.

What Does NOT Get Cached

• Videos at or over 300 MB (always streamed on all PWA devices)
• All content on Crestron AirMedia 200, Crestron Mercury, and Zoom Rooms on Windows (always streamed)
• Any content on a device with insufficient available cache storage — the player will detect this and stream instead

Device Storage — What You Need to Know

The PWA Player checks available storage before caching anything and will skip caching gracefully if space is insufficient — screens won’t crash, but they may stream content more than expected.

An important nuance: the PWA Player does not have access to the device’s full disk — the browser itself limits how much of the disk can be used for caching. In practice, the available cache is approximately 6–10% of the device’s total disk space, depending on the browser engine on that hardware. This means effective cache capacity is significantly smaller than the raw storage numbers might suggest.

⚠ Note: The 6–10% cache estimate is based on internal testing and is subject to change. Exact limits vary by device browser engine.

Content Planning Guidance

Because the browser caps how much disk space is available for caching, content planning matters on all PWA devices — not just those with small disks. Keep the following in mind:

• If the total size of a channel’s content exceeds the device’s available cache, the entire channel will stream from the network — not just the files that don’t fit
• PWA devices are not designed to run heavy content loads; lean playlists with smaller file sizes will always perform more reliably than content-heavy channels
• Keep video files under 300 MB and total playlist size well within the device’s estimated cache capacity

What Happens When the Network Goes Down?

Screens correctly report an Unhealthy status during network outages so administrators have visibility — but a screen that is still playing cached content will not generate a false alarm. The “Lost Communication” and “Offline” device statuses are based on how long the device has been fully unreachable, not whether it’s in the middle of a network blip.

Low Bandwidth Mode

To reduce bandwidth consumption, Low Bandwidth Mode is enabled by default on all PWA devices. This ensures that large video files do not stream automatically without an administrator making a deliberate choice to allow it. Admins can disable Low Bandwidth Mode from the Appspace Admin Console per device, which permits videos over 300 MB to play — though those files will always stream from the network rather than play from cache.

⚠ Note: PWA running Windows or MacOS do not currently support Low Bandwidth Mode.

Frequently Asked Questions

Will my screens keep playing if the internet goes out?

Yes — as long as the content is cached. Images, videos under 300 MB, and cards will all continue playing from the local cache. Videos at or over 300 MB always stream and will not play during an outage.

Why is a device streaming content instead of playing from cache?

The most common reason is that the total content assigned to the channel exceeds the device’s available cache storage — when this happens, the entire channel streams, not just the files that don’t fit. Other causes include a video file at or over 300 MB, or devices that do not support local caching trying to play content.

Is there a file size limit for images or cards?

No — there is no per-file size limit for images or cards. The 300 MB hard limit applies to video files only. However, the total combined size of all content in a channel still needs to fit within the device’s available cache storage.

Does caching happen automatically?

Yes. The PWA Player caches content in the background without any manual action required. Content is downloaded once and stored locally; subsequent plays use the cached copy.

How long is content cached?

Images, videos and cards are only cleared when the content is no longer assigned to the device

Does content need to be re-cached after an update?

No. The player manages this automatically. If content changes, the updated version is fetched and cached the next time the device syncs.

What happens to cached content when I unregister a device?

All contents except the app assets (player shell) are cleared automatically.