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Slow network performance can be caused by a congested connection, a bandwidth-hungry background application, a poor Wi-Fi signal, or misconfigured router settings. Rather than simply restarting your router and hoping for the best, work through the steps below to pinpoint the bottleneck and apply a targeted fix.
1

Run a Baseline Speed Test

Before changing anything, establish a measured baseline so you can tell objectively whether the steps you take are making a difference.
  1. Close all applications that might be using the network (browsers, email clients, cloud sync tools).
  2. Open a browser and navigate to speedtest.net or fast.com.
  3. Run the test and note your download speed, upload speed, and latency (ping).
  4. Compare the result against the plan speed listed on your ISP contract.
Run the test twice — once over Wi-Fi and once with a direct Ethernet cable plugged into the router. A large gap between the two readings points to a Wi-Fi problem rather than an ISP or router issue.
A result below 50% of your contracted speed during off-peak hours (early morning, weekends) is a strong indicator of an ISP-side problem or failing hardware. Save a screenshot of the results for your escalation report.
2

Check for Bandwidth-Heavy Applications

A single application downloading a large update or uploading files to the cloud can saturate your connection for everyone on the network.Windows — Task Manager:
  1. Press Ctrl + Shift + Esc to open Task Manager.
  2. Click the Performance tab, then Open Resource Monitor at the bottom.
  3. Switch to the Network tab in Resource Monitor.
  4. Look at the Processes with Network Activity section. Sort by Total (B/sec) to find the top consumers.
You can also use PowerShell to get a quick snapshot:
macOS — Activity Monitor:
  1. Open Activity Monitor (search with Spotlight: Cmd + Space, then type Activity Monitor).
  2. Click the Network tab at the top.
  3. Sort by Sent Bytes/sec or Rcvd Bytes/sec to identify the heaviest process.
Common culprits include: Windows Update, OneDrive/Dropbox/Google Drive sync, video conferencing software running in the background, antivirus definition updates, and game launchers.
Killing a process through Task Manager ends it immediately without saving its state. Pause cloud sync clients gracefully using their system tray icon before force-quitting them.
3

Check Wi-Fi Signal Strength

Even a network capable of gigabit speeds delivers far less if your device has a weak signal to the router.Windows:
  1. Hover over the Wi-Fi icon in the system tray — the tooltip shows signal bars.
  2. For a numeric dBm value, run:
Look for the Signal field. A value above 70% (roughly −65 dBm) is acceptable; below 50% (below −75 dBm) will cause noticeable slowdowns and packet loss.macOS:Hold Option and click the Wi-Fi menu bar icon. A pop-up shows RSSI (Received Signal Strength Indicator). Aim for −70 dBm or better.Improving signal strength:
  • Move closer to the router or access point.
  • Remove physical obstructions (walls, metal shelving, microwaves) from the signal path.
  • Reposition the router to a central, elevated location with its antennas vertical.
  • Consider a Wi-Fi extender or mesh node if the problem is distance-related.
Microwave ovens, baby monitors, and older Bluetooth devices operate on the 2.4 GHz band and can cause significant interference. If your router supports 5 GHz, switching to that band (see Step 4) can sidestep this interference.
4

Switch from Wi-Fi to a Wired Connection

A direct Ethernet connection eliminates radio interference, signal attenuation, and channel congestion in a single step.
  1. Plug one end of a Cat5e or Cat6 Ethernet cable into your computer’s network port and the other into an available LAN port on your router.
  2. On Windows, open Network Connections (ncpa.cpl) and confirm the Ethernet adapter shows Connected.
  3. On macOS, go to System Settings → Network and confirm Ethernet / USB Ethernet is active.
  4. Re-run your speed test from Step 1 and compare the result.
If the wired speed is dramatically better, the problem is isolated to your Wi-Fi setup. If the wired speed is also poor, the bottleneck is either the router, the modem, or the ISP.
If your laptop does not have an Ethernet port, a USB-C to Ethernet adapter or Thunderbolt dock with a built-in NIC works just as well and typically costs less than $20.
5

Check Router QoS Settings

Quality of Service (QoS) rules on your router prioritize certain types of traffic. A misconfigured QoS policy can accidentally throttle your device or your type of traffic.
  1. Open a browser and navigate to your router’s admin interface. Common addresses are 192.168.1.1, 192.168.0.1, or 10.0.0.1. Check the label on the underside of your router for the correct address and default credentials.
  2. Log in and locate the QoS, Traffic Management, or Bandwidth Control section (the label varies by manufacturer).
  3. Check whether any rules limit download or upload speed for your device’s IP or MAC address.
  4. Temporarily disable QoS entirely, re-run your speed test, then re-enable it if QoS was not the cause.
Router admin interfaces vary widely. If you are on a corporate or managed network, do not modify router settings without explicit permission from your IT administrator. Unauthorized changes can affect all users on the network.
Windows:
The Default Gateway line is your router’s admin IP address.macOS:
The first default entry in the output shows your gateway IP.Linux:
6

Test DNS Performance

A slow DNS server adds latency to every new connection your browser opens. Switching to a faster public DNS resolver is free and takes about two minutes.First, test your current DNS response time:
Compare that against a known-fast resolver:
If a public resolver is significantly faster, change your DNS settings:Windows:
  1. Open Network Connections (ncpa.cpl).
  2. Right-click your active adapter → Properties → Internet Protocol Version 4 (TCP/IPv4) → Properties.
  3. Select Use the following DNS server addresses and enter:
    • Preferred: 1.1.1.1
    • Alternate: 8.8.8.8
macOS:
  1. System Settings → Network → [Your Interface] → Details → DNS.
  2. Click + and add 1.1.1.1 and 8.8.8.8.
DNS changes take effect immediately for new connections. Already-open tabs in your browser may not benefit until you reload them.
7

Escalation Steps

If your speed remains well below the contracted rate after completing all steps above, it is time to involve additional support resources.
  • Speed test screenshots (Wi-Fi and wired, before and after each major step)
  • Router model and firmware version (found in the router admin page under Status or About)
  • Output of ipconfig /all (Windows) or ifconfig (macOS)
  • Peak vs. off-peak comparison — does the slowdown occur only during business hours or all day?
  • Number of affected devices — just yours, several, or all?
  • Recent changes — new devices added to the network, office furniture moved near the router, OS or firmware updates
  • ISP account details — contracted download/upload speed tier and current billing status
Persistent slow speeds that affect only one device but not others almost always point to a hardware fault (failing NIC or adapter) or a driver issue on that specific machine. Your IT support team can run deeper hardware diagnostics that are outside the scope of these steps.