What packet loss is and why it matters

Packet loss happens when data traveling across your network fails to reach its destination. Your computer breaks information into small pieces called packets. If some of those packets disappear between your device and the router, or between your router and the internet, you have packet loss. Even small amounts — 1 to 3 percent — can make video calls stutter, online games lag, or downloads stall.

Packet loss usually comes from three sources: a weak WiFi signal, a congested network with too many devices competing for bandwidth, or a problem with your internet service itself. Checking for it tells you whether the issue is inside your home network or outside it, which determines what you can actually fix.

Key Takeaways

  • Packet loss shows up as stuttering in video calls, lag in games, or stalled downloads, and you can measure it using the ping command on Windows, Mac, or Linux.
  • Run ping tests to a reliable server like 8.8.8.8 (Google's public DNS) for at least 100 packets to get a meaningful result, not just a handful.
  • If packet loss appears only on WiFi but not on a wired connection, the problem is your wireless signal or interference, not your internet service.
  • Packet loss that shows up on both wired and wireless connections usually means a problem with your modem, router, or internet service provider.
  • Tools like PingPlotter and MTR show you exactly where packets are being lost — at which hop between your device and the destination — which helps you narrow down the cause.

Using ping to measure packet loss

The simplest way to check packet loss is the ping command, which sends small test packets to a server and measures how many come back. On Windows, open Command Prompt (press Windows key + R, type cmd, and press Enter). On Mac or Linux, open Terminal. Type this command and press Enter:

ping -c 100 8.8.8.8 on Mac or Linux, or ping -n 100 8.8.8.8 on Windows. This sends 100 packets to Google's public DNS server at 8.8.8.8. Watch the results. At the end, you will see a line that says "X packets transmitted, Y packets received" or similar. If you sent 100 and received 100, you have zero packet loss. If you sent 100 and received 97, you have 3 percent packet loss.

Run the test multiple times — at least three separate runs of 100 packets each — because packet loss is often intermittent. A single test showing 0 percent loss does not mean you are safe if the next test shows 5 percent. Look for a pattern. If every test shows some loss, the problem is consistent. If loss appears randomly, something is interfering with your signal or your network is overloaded at certain times.

Testing WiFi versus wired connections

The fastest way to find the source of packet loss is to test both. If you have a device that can connect with an Ethernet cable, plug it in directly to your router and run the ping test again. Compare the results to the WiFi test you just ran.

If the wired connection shows zero or near-zero packet loss but WiFi shows 2 percent or higher, the problem is your wireless signal. Move closer to the router, check for interference from microwaves or cordless phones on the 2.4 GHz band, or switch to the 5 GHz band if your router supports it. If both wired and wireless show the same packet loss, the problem is not your WiFi — it is your modem, router, or internet service.

Not every device has an Ethernet port. If you cannot test wired, move your WiFi device as close to the router as possible and run the test again. If packet loss drops significantly, signal strength is the issue. If it stays the same, something else is wrong.

Using PingPlotter to find where packets are lost

Ping tells you whether you have packet loss, but not where it happens. PingPlotter (available free at pingplotter.com) shows you the path your packets take — each "hop" from your device to the destination — and which hop is losing packets. read the free version, install it, and enter 8.8.8.8 in the target field. Let it run for a few minutes.

The graph shows each hop as a row. If one row is red or orange while others are green, packets are being lost at that hop. If the first hop (your router) is red, the problem is inside your home network. If hops 2 through 5 are green but hop 6 or later is red, the problem is outside your home — likely your internet service provider.

PingPlotter is most useful when you already know you have packet loss and need to know whether to call your ISP or fix something at home. If the loss is happening at your router or the first few hops, troubleshoot your network. If it is happening several hops away, contact your ISP and tell them which hop is losing packets — they can investigate from their end.

Using MTR for detailed network diagnostics

MTR (My Traceroute) combines ping and traceroute into one tool and is built into Mac and Linux. Windows users can read WinMTR. Open Terminal or Command Prompt and type mtr 8.8.8.8. Let it run for at least 100 packets (it will show a count at the bottom).

MTR displays each hop with columns for Loss%, Snt (packets sent), Last (most recent response time), Avg (average response time), Best, and Worst. The Loss% column tells you when ready which hop is dropping packets. A hop showing 5% loss while others show 0% is your culprit. Run MTR several times to confirm the pattern, because some loss is intermittent.

MTR is more detailed than PingPlotter but takes longer to read. Use it when you need exact percentages for each hop or when you plan to contact your ISP and want precise data to share with them.

What to do if you find packet loss

If packet loss appears only on WiFi, start with the simplest fixes: move closer to the router, reduce the number of devices connected, and check for interference. Microwaves, baby monitors, and cordless phones on 2.4 GHz can cause packet loss even if they are in another room. Switch to 5 GHz if your router and devices support it — fewer devices use that band, so interference is less common.

If packet loss appears on both wired and wireless connections, restart your modem and router. Unplug the modem, wait 30 seconds, plug it back in, and wait for all lights to stabilize. Then do the same for the router. Run the ping test again. If packet loss persists, check your modem's connection to the wall — make sure the coaxial cable is hand-tight. If that does not help, contact your ISP and tell them you are seeing consistent packet loss on a wired connection. Provide the hop number where loss occurs if you ran PingPlotter or MTR.

If packet loss is intermittent and only happens during certain times of day, your network may be congested. Too many devices streaming video or downloading at once can overwhelm your router. Check how many devices are connected and what they are doing. Limit bandwidth-heavy activities or upgrade to a router that handles more simultaneous connections.

When to upgrade your equipment

If you have ruled out WiFi signal issues and your ISP confirms no problems on their end, the issue may be your router or modem. Routers older than five years often struggle with modern networks. If you have 20 or more devices connected, or if you regularly stream 4K video and play online games at the same time, an older router may not keep up.

Contact your ISP first — they may provide a newer modem at no cost if yours is old. If you own your modem, check its age and specifications. Modems designed for older internet speeds may not handle current service well. If your router is the problem, look for one that supports WiFi 6 (802.11ax) and has multiple antennas, which reduces packet loss on wireless connections.

Frequently Asked Questions

How much packet loss is acceptable?

Zero is ideal, but 1 percent or less is usually unnoticeable for most activities. Video calls and streaming tolerate up to 2 to 3 percent. Online games become unplayable above 5 percent. If you see 3 percent or higher consistently, investigate the cause.

Can packet loss happen only on certain websites or apps?

Yes. If packet loss appears only when you use one app or visit one website, the problem is usually that service's server or the route to it, not your network. Test with a different destination — try pinging 1.1.1.1 (Cloudflare's DNS) instead of 8.8.8.8. If the second test shows no loss, the first destination is the issue.

Does restarting my router always fix packet loss?

Restarting fixes packet loss caused by the router overheating or running out of memory, which is common. It does not fix packet loss caused by weak WiFi signal, interference, or problems outside your home. Always test again after restarting to see if it helped.

What is a normal ping time?

Ping times under 50 milliseconds are excellent. 50 to 100 milliseconds is good for most uses. Above 100 milliseconds, you may notice lag in games or slight delays in video calls. Ping time and packet loss are separate — you can have low ping but high packet loss, or high ping but zero loss.

Should I test packet loss to my router or to the internet?

Test to the internet (like 8.8.8.8) first. If that shows packet loss, then test to your router's IP address (usually 192.168.1.1) to see if the problem is inside or outside your home. If internet tests show loss but router tests show zero, the problem is between your router and your ISP.