How to Fix Packet Loss

Step 1: Confirm packet loss with a test

Run ping -c 100 8.8.8.8 in Terminal (macOS/Linux) or ping -n 100 8.8.8.8 in Command Prompt (Windows). Any result above 0% lost is packet loss. Also run a speed test and note if the result is unstable (varies wildly between runs).

Step 2: Test on wired Ethernet

If you are on Wi-Fi, connect via Ethernet and retest. Wi-Fi causes intermittent packet loss from signal interference. If packet loss disappears on wired: Wi-Fi interference is the cause — see the Wi-Fi fix guide. If packet loss persists on wired: the problem is hardware or ISP-side.

Step 3: Inspect physical cables

A damaged, kinked, or overly long coaxial cable is the most common cause of cable internet packet loss. Inspect the coax from your modem to the wall outlet — replace any cable with visible damage, sharp bends, or corrosion on the connector. Also replace any Ethernet cable that has been pinched under furniture or a door.

Step 4: Replace or restart the modem

A failing modem generates uncorrectable errors that appear as packet loss. Restart the modem (30-second full power-off). If packet loss reduces: the modem needed a connection reset. If packet loss persists: the modem may be failing — check its event log in the admin interface for 'T3' or 'T4' timeout errors, which indicate line problems.

Step 5: Isolate the router

Connect a device directly to the modem (bypassing the router) and retest. If packet loss disappears: the router is the cause — update firmware, restart, or replace. If packet loss continues directly to the modem: the problem is the ISP line or modem.

Step 6: Call your ISP

Persistent wired packet loss that survives modem restarts is almost always an ISP-side issue — a degraded drop cable, corroded splice point, or congested node. Request a line inspection. Ask the technician to check 'uncorrectable codewords' in the modem log and signal-to-noise ratio on the line.

Frequently Asked Questions

How much packet loss is acceptable?

0% is the target. Under 0.5% is acceptable for most downloads — TCP retransmits correct it transparently. Over 1% is noticeable for video calls and gaming. Over 3% is severe and will visibly degrade any real-time application.

Can packet loss be fixed with a VPN?

Sometimes — a VPN can bypass a congested or misconfigured ISP routing path. But if the loss is on the physical line between your home and the ISP node, a VPN cannot fix it (the packets are lost before they reach the VPN server). Test with and without a VPN to see if the loss is routing-related or physical.

Does packet loss affect streaming?

Buffered streaming (Netflix, YouTube) absorbs occasional packet loss without noticeable effect — the buffer compensates. Real-time streaming (Twitch, Zoom, Teams) has no buffer, so even 0.5% loss causes degradation: pixelation, audio drops, and freezes.