How to test your internet speed (and what the results mean)

A speed test measures three things: download speed (data coming to you), upload speed (data leaving you), and ping or latency (how quickly data starts moving). The whole test takes 30 seconds. The information it gives you is valuable both for troubleshooting slow internet and for confirming you are getting what you pay for.

The best speed tests

fast.com

Run by Netflix. Simple, free, ad-free. Tests download speed automatically and shows upload + latency in the advanced view. Best for quick checks.

speedtest.net

Run by Ookla. More detailed than fast.com. Shows specific test server locations (useful for testing latency to game servers or distant cities). Free with optional ads.

speedtest from Cloudflare (speed.cloudflare.com)

Newer option. Tests via Cloudflare's global network. Cleaner interface than Ookla. Useful when other tests give inconsistent results.

Avoid ISP-run speed tests

ISP-run speed tests (Xfinity Speed Test, AT&T Speed Test) typically connect to nearby ISP servers and produce optimistic results. Use independent tests to get honest numbers.

How to test correctly

Use a wired Ethernet connection if possible

Wi-Fi adds variables: distance, walls, interference. Testing over Wi-Fi tells you what your Wi-Fi delivers, not what your internet plan delivers. Plug your computer directly into the router with an Ethernet cable for the most accurate test.

Close other apps and downloads

Anything actively using bandwidth (Netflix in another tab, cloud syncing, automatic updates) reduces the available bandwidth during the test. Close everything else first.

Test multiple times

Run the test 3-5 times across different times of day. Cable internet often shows different speeds at peak hours (evenings, weekends) than at off-peak. Note the variation.

Test from the room you actually use

If you mostly use your phone in the back bedroom, test Wi-Fi from the back bedroom. Speed at the router does not necessarily reflect speed where you actually need it.

What the results mean

Download speed

Compare to your ISP plan. Getting 80%+ of advertised? Normal. Getting under 70% consistently? Worth investigating.

Common reasons for low results: Wi-Fi limitations, old router, peak hour congestion on cable networks, or actual ISP throttling.

Upload speed

Cable plans typically deliver 10-35 Mbps upload regardless of download tier. Fiber plans deliver symmetric upload matching the download. Compare to what your plan promises.

Latency (ping)

Under 20ms: excellent (fiber typical).

20-40ms: good (cable typical).

40-60ms: acceptable (5G Home Internet typical).

60-100ms: usable for streaming, noticeable for gaming.

100ms+: causes lag in video calls and gaming.

Speed test troubleshooting

Speeds drop only on Wi-Fi

Your Wi-Fi router is the bottleneck. Upgrade to a newer router or move closer to the existing one. Mesh systems extend coverage effectively.

Speeds drop at certain times

Cable peak-hour congestion. Run tests at 6 AM and 8 PM on the same day to confirm. ISPs cannot promise consistent speeds during congestion on shared cable networks.

Speeds drop suddenly

Check ISP outages first (downdetector.com aggregates user reports). Restart modem and router. If the drop persists, contact your ISP - this often indicates an issue on their side.

Speeds are always low

You may need a faster plan. Compare your speed test results to a competitor's offerings. If alternate ISPs at your address offer faster service at similar prices, consider switching.

When to contact your ISP

Consistently under 70% of advertised speeds via wired Ethernet for more than three days. This typically indicates an issue with the line, your modem, or your ISP's configuration. Open a ticket with screenshot evidence.