YouTube error · Common
YouTube plays 1 second then buffers forever — fix the false start
The video starts playing, runs for 1-2 seconds, then hangs on a buffering spinner forever even though your connection is good. Distinct from steady buffering — this is the player's first-buffer being immediately drained.
Why this happens
- CDN edge near you served the first segment from cache, then can't deliver the next one (cache miss on a slow edge).
- Adaptive bitrate algorithm sampled the first segment's fast cached delivery, picked a high quality, then the second segment from a different (slow) source can't keep up.
- Mobile data saver active — the carrier shaped traffic differently mid-stream.
- Player JS bug after long page idle.
How to fix it
- 1
Lower the quality
Gear → Quality → 480p. If the lower-bitrate stream plays without stalling, ABR's initial high-quality pick was wrong.
- 2
Hard reload
Cmd+Shift+R. Player state resets, new ABR session starts. Fixes most one-off stalls.
- 3
Try a different CDN edge (different DNS or VPN)
Switching DNS to 1.1.1.1 or briefly connecting to a VPN routes you to a different CDN edge. If the new edge is healthier, the buffer fills.
- 4
Download instead
When the player can't maintain steady playback, downloading once and watching locally works. No CDN edge dependencies, no ABR.
Frequently asked
Why does the first second always cache?
YouTube's player pre-fetches the first ~5 seconds before starting playback so the start is instant. The pre-fetch comes from any edge; subsequent segments come from a specific edge optimized for your IP. The two paths can have different speeds.