Question 1

Why does my result differ from Speedtest.net or Fast.com?

Accepted Answer

This is normal, not a sign that either test is wrong. Each service measures against different servers in different locations, uses a different number of parallel connections, and — most importantly — your connection's real capacity genuinely fluctuates minute to minute depending on network congestion, what else is happening on your Wi-Fi, and your ISP's own traffic load at that moment. For a fair comparison, run tests within about a minute of each other; even then, some gap is expected.

Question 2

What's a good internet speed?

Accepted Answer

It depends entirely on what you're doing. Standard-definition video calling needs roughly 3-4 Mbps, HD video streaming around 5-10 Mbps, and 4K streaming closer to 25 Mbps — but those are per-stream figures, so a household running several devices at once needs the sum of all of them. Competitive online gaming cares far more about low, stable ping and jitter than about raw Mbps once you're above roughly 10-15 Mbps.

Question 3

What is ping, and why does it matter?

Accepted Answer

Ping (latency) is the round-trip time for a small packet to reach a server and come back, measured in milliseconds — lower is better. It matters most for anything real-time: video calls, voice chat, and online gaming all feel laggy when ping is high, even if your download speed is excellent, because latency determines how quickly your actions and the other side's responses actually arrive.

Question 4

What is jitter?

Accepted Answer

Jitter is how much your ping varies from one moment to the next, rather than the ping value itself. A connection that holds steady at 40ms is often more pleasant for a video call than one that averages 25ms but keeps swinging between 5ms and 90ms, because that inconsistency is what causes audio to cut out or video to freeze momentarily.

Question 5

What is bufferbloat, and why do my loaded ping numbers matter?

Accepted Answer

Bufferbloat happens when your router or modem queues up far more data than it can actually send, so that queue itself adds delay — sometimes hundreds of milliseconds — on top of your connection's normal latency. SpeedFast measures ping separately while idle and while your download or upload is actively running; if the loaded numbers jump dramatically compared to idle, that gap is bufferbloat, and it's exactly what makes video calls stutter during a large download even though your Mbps number looks fine.

Question 6

Why is my upload speed so much lower than my download?

Accepted Answer

Most home and mobile connections are deliberately asymmetric — cable, DSL, and most cellular technologies allocate far more capacity to downloads than uploads, since the average household downloads far more than it uploads. This is a property of your connection type and plan, not something a speed test can change; if you regularly upload large files or livestream, it's worth checking whether your ISP offers a plan with better upload speed.

Question 7

Does Wi-Fi affect my result?

Accepted Answer

Yes, often significantly. Wi-Fi introduces its own variables — distance from the router, interference from walls and other networks, and the Wi-Fi standard your device supports — that can cap your result well below what your internet plan actually provides. If you want to measure your connection itself rather than your Wi-Fi, run the test from a device connected by ethernet cable.

Question 8

Can other devices on my network affect the test?

Accepted Answer

Yes. A speed test measures whatever capacity is actually available at that moment, so a household member streaming 4K video, a large cloud backup running in the background, or another device mid-download will all reduce what's left for your test — accurately reflecting your real, shared experience, not a flaw in the measurement.

Question 9

Is SpeedFast free, and do I need an account?

Accepted Answer

Yes — SpeedFast is free to use and requires no sign-up or account. You can optionally save a shareable link to any individual result, but running the test itself has no login wall.

Question 10

What information does SpeedFast collect about me?

Accepted Answer

Only what's needed to run the test and show you a meaningful result: your approximate location and ISP (derived from your IP address, which is partially masked before storage — see our Privacy Policy for the exact details), and the speed/latency numbers themselves. Your test history is stored locally in your own browser, not on our servers, unless you explicitly save a shareable result.

Question 11

Can anyone see my result if I share the link?

Accepted Answer

A shared result link shows the speed, latency, and general ISP/location information for that specific test — the same kind of summary you'd see on the page yourself. It does not expose your full IP address or any personally identifying information beyond what's already visible in the result card.

Frequently Asked Questions