Elymica is designed to work across Africa’s real network conditions: 2G, 3G, patchy Wi-Fi, and shared data plans. This guide explains how the platform handles low-bandwidth situations, what content is available offline, and how to prepare before going offline.
How Caching Works
Elymica is built as a Progressive Web App (PWA). When a student or teacher opens the platform, the app shell (navigation, layout, and core interface) is cached on the device automatically. This means the platform loads immediately on repeat visits, even before content has fully loaded.
Beyond the app shell, Elymica caches content in layers:
Layer 1: Course index: The list of enrolled courses, their metadata, and progress state is always kept current in local storage. Students can always see what they are enrolled in, and their progress is preserved, even without a connection.
Layer 2: Active lesson: When a student opens a lesson, the text and any lightweight assets (images, PDFs) are cached as they load. If the connection drops mid-session, the student can continue reading from cache.
Layer 3: Pre-fetched content (Wi-Fi required): When connected to Wi-Fi, Elymica pre-fetches the next 3 lessons in a course. This makes moving through a course smooth even on a mobile data connection. Most content has already downloaded by the time the student reaches it.
What Works Without Any Connection
With no connection at all, students and teachers can:
- View all enrolled courses and progress state
- Read any lesson already opened in the current session
- Review completed lessons from cache
- Access any content pre-fetched on a previous Wi-Fi session
What requires a connection:
- Submitting quiz answers (answers are queued and submitted when connection returns)
- Loading new lessons not yet cached
- Viewing video content (videos are not cached by default due to file size)
- Receiving new messages or notifications
Quiz Submission Queue
If a student completes a quiz while offline, their answers are held in a local submission queue. The queue syncs automatically when the connection returns, usually within seconds if the device reconnects, or on the next app open. The timestamp of the original submission is preserved.
Teachers and admins see quiz results populated as the queue syncs. There is no manual step required.
Video Content on Low Bandwidth
Videos are the most data-intensive content type. Elymica uses adaptive bitrate streaming: on a 2G connection, video quality is reduced automatically to maintain playback without buffering. On 3G, standard quality is served. On Wi-Fi or 4G+, full quality plays.
Publishers are required to provide a transcript for every video lesson. If a student cannot buffer video at all, they can switch to the transcript view to read the lesson content without consuming data.
To check connection quality before a video lesson, the player shows the current quality level in the bottom-right corner. Tapping it allows the student to manually lock to a lower quality if their data budget is limited.
Setting Up Before Going Offline
For teachers preparing for a low-connectivity classroom:
- Open the Elymica app on the classroom device (tablet or shared laptop) while on Wi-Fi.
- Open the course the students will work on.
- Open each lesson in sequence. This caches text and images for all lessons.
- If the session will include quizzes, open each quiz page to ensure the question content is cached.
- The classroom device will now serve the lesson content without a connection during the session.
For students on mobile data:
- Download lessons the night before when connected to Wi-Fi, not on mobile data.
- The pre-fetch feature does this automatically after opening 3+ lessons on Wi-Fi.
- Check the small cache indicator icon on the lesson card (grey = not cached, green = ready offline).
Sync Behaviour After Reconnecting
When a device reconnects:
- Queued quiz submissions are sent immediately.
- Progress state (lessons completed, time spent) syncs to the server.
- Any new messages or announcements are fetched.
- New lessons available in enrolled courses are indexed. Only the metadata updates; the full lesson content is not downloaded.
The sync process runs in the background and completes in under 30 seconds on a typical 3G connection. No user action is required.
For School Administrators: Monitoring Offline Usage
The admin dashboard shows a Connectivity Insights panel under Reports. This displays:
- Percentage of student sessions that included an offline period
- Average offline duration per session
- Lessons most frequently accessed in offline mode (useful for planning pre-fetch priorities)
If a significant portion of students are regularly going offline, this panel helps identify which content to prioritise for pre-fetching and whether the school should invest in a local Wi-Fi hotspot or offline content server.
Written by Elymica Editorial · Editorial Team
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