Why Is My Speed Test Showing 0? Common Causes and Fixes

If your speed test shows 0 Mbps, it usually means the test could not measure a usable connection rather than proving your internet is literally zero. The cause can be local, such as Wi-Fi interference or a router problem, or upstream, such as an ISP outage or a blocked test.

What a 0 Mbps result usually means

A result of 0 for download or upload often appears when the test cannot complete a data transfer. That can happen if the connection drops during the test, the device cannot reach the test server, or another app interferes with the measurement.

In some cases, the number is not a real throughput reading at all. It may be a browser issue, a DNS problem, a VPN conflict, or a temporary failure between your device and the speed test server.

Common reason: your ISP connection is down or unstable

If the modem has lost sync, the line is degraded, or the provider has an outage, a speed test may stall at 0. This is more likely if every device in the home sees the same result on both Wi-Fi and Ethernet.

Check whether websites load at all, and compare the result on a second device. If the whole home network is affected, restart the modem and router, then check your ISP status page or support app for outage alerts.

Common reason: Wi-Fi signal is too weak

A weak Wi-Fi signal can cause packets to drop before the speed test finishes, especially on crowded 2.4 GHz channels or when the device is far from the router. In that case, the test may never get enough stable traffic to report a real number.

Move closer to the router and run the test again. If the result improves on a wired Ethernet connection, the issue is likely Wi-Fi related rather than a broadband line problem.

Common reason: the router or modem needs attention

A router with an overloaded CPU, outdated firmware, or a bad WAN session can break speed tests even if basic browsing still works. Modem signal issues, failing cables, or a damaged port can cause the same symptom.

Power-cycle the modem and router, confirm the cables are seated firmly, and check for firmware updates. If the device stays unstable after a restart, test with another router or modem if possible.

Common reason: device settings or software are interfering

VPNs, security tools, bandwidth limits, background sync, and firewalls can interfere with a speed test. Some browsers also misbehave if extensions block scripts or if hardware acceleration causes rendering issues.

Try the test in a private window, disable the VPN, pause large downloads, and close cloud backup or game launchers. If the result changes after that, the problem is likely on the device rather than the network line.

Common reason: the test server or browser cannot complete the session

Sometimes the issue is the test path itself. A congested server, a blocked WebSocket, stale DNS data, or an outdated browser can prevent the test from loading traffic properly.

Run a second speed test from a different site and, if needed, a different browser. If only one test shows 0, the problem is probably with the test environment, not your internet connection.

How to narrow down the cause quickly

Use a simple isolation order

1. Test on a second device.
2. Switch from Wi-Fi to Ethernet if possible.
3. Disable VPN and pause background apps.
4. Restart the modem and router.
5. Try another speed test server or browser.

If the result changes at any step, the last change points to the likely cause. That makes it easier to tell whether you need to adjust local equipment or contact your ISP.

What you can do to fix it

If the issue is Wi-Fi, improve signal quality by moving the router, changing channels, or using a mesh node. If the issue is the router or modem, update firmware, replace damaged cables, and reboot the hardware.

If the issue is a device setting, disable the VPN, pause security scans temporarily, and close bandwidth-heavy apps. If the issue persists across devices and connections, contact your ISP and report that speed tests are failing at 0 Mbps on both download and upload.