Prime Video buffering — fix it

Prime Video HD needs 5 Mbps sustained, 4K needs 25 Mbps. Plus reliable CDN reach.

Prime Video buffering means sustained throughput dropped below the bitrate of the video stream you're watching. Prime Video AWS CloudFront CDN — varies by ISP peering quality.

Signalyzr measures sustained throughput (not peak) and CDN reachability — the actual metrics that decide whether Prime Video buffers.

What this measures

  • Sustained download (needs to be ≥ 5 Mbps for HD, 25 Mbps for 4K)
  • Latency to nearest probe
  • DNS resolution time

How it works

  1. Test
  2. Compare against the threshold
  3. Identify cause
  4. Fix

Why this matters

Peak speed lies. Prime Video needs SUSTAINED speed. Signalyzr measures sustained.

Top fixes

  • If speed is fine but Prime Video buffers: try changing DNS to 1.1.1.1
  • If only Prime Video buffers (other sites fine): try Prime Video on a different device — possibly app cache
  • If everything buffers: it's connection-wide (speed, jitter, packet loss)

FAQs

Why does Prime Video buffer in HD when speed test says 200 Mbps?

Speed tests measure peak. Streaming needs sustained over 5-10 minutes. ISP throttling, CDN issues, or Wi-Fi dropouts can be invisible to a 15-second speed test.

Is Prime Video blocked by my ISP?

Rare in India. Almost always either weak Wi-Fi, peak congestion, or app cache issues. Diagnose first.

Diagnose Prime Video →

Related

Signalyzr is a free, privacy-first network diagnostic tool made in India. Loading the diagnostic app…