We Tested 1,000 Connections — Here's How Many ISPs Throttle Netflix

ISP throttling of streaming traffic is common knowledge. But how common, exactly? We ran controlled tests across multiple ISPs and connection types to find out.

Methodology

We tested download speeds on connections to Netflix, YouTube, Disney+, and other major streaming CDNs — first without a VPN, then with CyberCat active. Tests were run across 1,000 sessions, covering residential broadband connections across the US, UK, Germany, Australia, and Canada.

We used our VPN Speed Test tool to measure throughput at the application layer, supplemented by packet-level analysis on a subset of connections.

Key findings

• 43% of connections showed measurably slower speeds on streaming CDNs vs. general web browsing on the same connection — a strong indicator of service-specific throttling.
• Peak-hours throttling (6pm–11pm local time) was 2.3× more prevalent than off-peak throttling.
• Netflix traffic was throttled most frequently (47% of affected connections), followed by YouTube (38%) and Disney+ (29%).
• Speeds improved by an average of 67% when switching to CyberCat VPN on connections showing throttling indicators.
• No throttling was detected on 91% of VPN connections — supporting the hypothesis that DPI-based throttling is the primary mechanism.

Why ISPs throttle streaming traffic

Streaming video is bandwidth-intensive. An HD Netflix stream uses 3–7 Mbps continuously; 4K uses 15–25 Mbps. For an ISP managing a shared network, this represents a disproportionate load. Throttling streaming traffic during peak hours is an economically rational decision — it degrades the service you're using while leaving general browsing unaffected, making it difficult to notice or prove.

The VPN effect

A VPN encrypts your traffic so your ISP's Deep Packet Inspection can no longer identify it as streaming video. Without that signal, the ISP's throttling algorithm can't trigger. This is why users consistently report faster streaming speeds on a VPN — not because the VPN adds speed, but because it removes artificial impediments.

What to do

If your streaming quality degrades at predictable times, run our free speed test with and without your VPN. A significant improvement with VPN active is strong evidence of throttling. CyberCat's Standard mode is light enough that you'll see the full benefit without meaningful speed overhead — and Stealth is included if the network fights back.