How to Fix Packet Loss — Step-by-Step Diagnosis and Fixes
Packet loss causes game stuttering, video call freezes, and dropped audio — even when your speed test looks fine. Test your connection at instantspeedtest.net/ and note any packet loss percentage shown during the test.
Packet Loss Causes — From Most to Least Common
| Cause | How to Diagnose | Fix |
|---|---|---|
| WiFi interference or weak signal | Packet loss disappears on Ethernet | Switch to Ethernet; fix WiFi dead zone |
| Faulty Ethernet cable | Packet loss persists on Ethernet; try new cable | Replace Cat6 cable |
| ISP network congestion | Packet loss at specific times of day | Document; escalate to ISP |
| Modem or router hardware fault | Packet loss on all devices simultaneously | Restart hardware; test modem logs for T3/T4 errors |
| Outdated NIC driver (Windows) | Packet loss on one device only | Update NIC driver from manufacturer |
| ISP line signal degradation | Modem shows signal errors; line noise | Request ISP technician to check line quality |
| Game server-side packet loss | Packet loss only in specific games | Report to game developer; use different server region |
Running a Traceroute to Find Where Packet Loss Occurs
A traceroute shows each network hop between you and a destination — revealing exactly where packets are dropping. Windows: open Command Prompt → tracert 8.8.8.8. Mac/Linux: Terminal → traceroute 8.8.8.8. Look for hops showing Request timed out or high loss percentages. Loss in hop 1 (your router) = local network issue. Loss in hops 2–4 = ISP infrastructure. Loss only starting at specific hop = that ISP node or peer connection is the problem — relay this traceroute to your ISP for investigation. Note: some hops deliberately don’t respond to traceroute pings (ICMP filtering) — this is normal and not necessarily real packet loss. See our packet loss explainer.
Related Guides
- What Is Packet Loss?
- Wired vs Wireless Speed
- Fix High Jitter
- Improve Gaming Ping
- Modem vs Router
- Fiber vs Cable Internet
Frequently Asked Questions
What percentage of packet loss is acceptable?
For general internet use: under 1% is acceptable. For gaming: 0% is the target — even 0.5% packet loss causes noticeable hit registration issues and stuttering. For VoIP calls: under 0.5% is acceptable; above 1% causes audible dropouts. Video streaming buffers against packet loss better — 1–2% is manageable with buffering, 5%+ causes visible freeze-and-skip. Any consistent packet loss above 0% is worth investigating, particularly for real-time applications.
Can packet loss affect download speed?
Yes significantly — TCP (the protocol used for downloads) retransmits lost packets. Each lost packet triggers a retransmission and a congestion-avoidance slowdown. 1% packet loss can reduce TCP download throughput by 10–30%. 5% packet loss can reduce throughput by 50–70%. This is why connections with packet loss often test slower than their plan speed even when the physical link is capable of higher rates. Fixing packet loss frequently improves measured download speed simultaneously.