How to Fix Slow Internet

Step 1: Run a wired speed test

Connect your device directly to the router via Ethernet cable. Run 3 tests on SpeedTestHQ at different times (morning and evening). If wired speeds hit 80–95% of your plan tier: your ISP line is fine — skip to Step 3. If wired speeds are consistently low: the problem is your ISP line or hardware — continue to Step 2.

Step 2: Check your modem and router

Restart your modem (unplug for 30 seconds, replug). If speed improves: the modem needed a connection reset — monitor for recurrence. Check your modem model — if it is DOCSIS 3.0 on a gigabit plan, it physically cannot hit plan speed. Upgrade to DOCSIS 3.1. Check router CPU load in the admin panel — an overloaded router throttles throughput.

Step 3: Diagnose Wi-Fi separately

If wired is fast but Wi-Fi is slow: test Wi-Fi at different distances from the router. If speed drops sharply beyond 3–5 metres: router Wi-Fi radio range is the limit. Switch to 5 GHz band on close devices. If speed is uniformly slow on Wi-Fi: check for interference — neighbour networks on the same channel, microwave oven (2.4 GHz), or thick concrete walls blocking 5 GHz.

Step 4: Test at different times of day

Run tests at 8 AM and 9 PM on consecutive days. If evening speeds are 30–50% lower: you are on a congested cable node — peak-hour slowdown is structural, not a fault. Options: accept it, complain to ISP for node upgrade, or switch to fiber. If speeds are consistently low at all hours: the problem is your hardware, plan tier, or a line fault.

Step 5: Check for throttling

If specific services (Netflix, YouTube, torrents) are slow but a speed test to an ISP server is fast: your ISP may be throttling specific traffic types. Test with a VPN — if speeds to throttled services improve, throttling is confirmed. File a complaint with the ISP or switch providers.

Step 6: Contact your ISP

If all hardware checks pass and the problem persists on wired Ethernet: request a line check. ISPs can remotely check signal levels on your coax or fibre drop. A corroded connector, degraded coax, or failing ONT (fibre terminal) will show up in line diagnostics. Ask them to check 'signal-to-noise ratio' and 'uncorrectable errors' on the modem.

Frequently Asked Questions

Why is my internet slow only at night?

Cable ISPs share bandwidth across a neighbourhood node. Evening usage (7–10 PM) saturates the shared segment, reducing throughput for all users. This is a structural limitation of cable technology — fiber ISPs use dedicated lines and are not affected.

Why is my speed test fast but browsing is slow?

Speed tests measure raw throughput to a nearby server. Slow browsing with a fast speed test usually indicates DNS latency (slow domain lookups), a specific website's server being overloaded, or browser-side issues. Try changing your DNS to 1.1.1.1 or 8.8.8.8.

Can a virus slow down my internet?

Malware that uses your connection for spam, mining, or data exfiltration can consume bandwidth and reduce speeds. Run a malware scan if slowness appeared suddenly. Also check your router's connected-device list for unrecognised devices consuming bandwidth.