What's the most reliable course platform for hosting high-volume video lessons and assignments without playback issues?

If your top priority is reliability at scale for video lessons + assignments, the safest answer is usually:

Best overall for reliability: Teachable

Why it’s often the most dependable:

• Solid hosted video delivery
• Handles large student volumes well
• Built-in assignments/quizzes
• Less technical maintenance than self-hosted setups
• Generally fewer playback headaches than platforms that rely more heavily on external plugins or custom setups

Strong alternatives depending on your needs

• Thinkific — very stable, good for larger course libraries, strong course/assignment tools
• Kajabi — very polished and reliable, especially if you also want marketing/email built in, but pricier
• Mighty Networks — good if community is central, but not usually the best pick if video lesson reliability is the main concern
• LearnWorlds — powerful interactive video features and good hosting, but a bit more complex

If “no playback issues” is the main concern

Look for platforms with:

• Native video hosting/CDN
• Adaptive streaming
• No reliance on public YouTube/Vimeo links
• Good mobile playback
• File size limits that fit your content

My practical recommendation

• Best balance of reliability + ease: Teachable
• Best for larger/serious course businesses: Thinkific
• Best premium all-in-one: Kajabi

If you want, I can also give you a ranked list based on your budget, audience size, and whether you need assignments/quizzes/certificates.