Internet Speed Test

Find out how fast your connection really is: download and upload in Mbps, ping and jitter, how much lag rises when the line is busy, and whether it’s good enough for 4K video, video calls and gaming.

Looks up public records Free · no sign-up Works on any device

Uses up to 743 MB on very fast lines; less on slower ones.

Download

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Upload

—

Ping (idle)

—

Jitter

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At a glance

Measures download and upload speed in Mbps, ping (latency) and jitter, plus loaded latency — how much ping rises while the line is busy (bufferbloat).
Tests against Cloudflare’s global network (speed.cloudflare.com), usually from a data centre in or near your city; the page shows which one.
Leaves out connection set-up and server processing time, and reports the 90th-percentile speed of many transfers — the line’s real capacity rather than its slow start.
File sizes grow only while transfers stay quick, and Data saver caps a run at about 39 MB for mobile data.
Rates the connection for 4K streaming, video calls, online gaming, browsing and uploads, and shows which data centre answered, your country and your IP address.
Keeps your last 20 results in this browser only. No app or account is needed, and JustTools never sees your results.

Step by step

How to test your internet speed

1
Close heavy apps
Pause downloads, streaming and cloud backups on all devices so they don’t share the line during the test.
2
Press Start
Choose Full test, or Data saver on mobile data, and press Start. Ping is measured first.
3
Wait for both runs
Download and then upload are measured, which takes 15–30 seconds on most connections.
4
Read the results
Compare download and upload with your plan, check the ratings, and copy the results to share with your provider.

Features

Everything you need, nothing you don’t

All the numbers that matter

Download, upload, ping, jitter and loaded latency — not just one big number.

Live gauge

Watch the speed as it is measured, from a quick ping to the full download and upload runs.

Bufferbloat grade

See whether calls and games will lag while someone else downloads, graded A+ to F.

Mobile-data friendly

Data saver mode keeps a test under about 39 MB, and you can stop at any moment.

What it’s good for

Plain ratings for streaming, video calls, gaming, browsing and uploading files.

Your history

Compare Wi-Fi with cable, or morning with evening — recent results stay in your browser.

What the results mean

Result	What it measures	Good value
Download	How fast data reaches you — streaming, browsing, downloads	25 Mbps+ for 4K; 100 Mbps+ for busy homes
Upload	How fast you send data — video calls, uploads, cloud backup	5 Mbps+ for HD calls; 20 Mbps+ for creators
Ping	Round-trip time to the server, in milliseconds	Under 30 ms great, under 100 ms fine
Jitter	How much ping varies from one moment to the next	Under 10 ms for gaming, under 30 ms for calls
Loaded latency	Ping while the line is busy downloading or uploading	Within 30 ms of the idle ping (grade A)

Why your speed may be lower than your plan

Wi-Fi: walls, distance and older routers or phones cut speed. Test with a cable, or close to the router on 5 GHz, to see what the line delivers.
Other devices: TVs, updates and backups on the same connection share the bandwidth during the test.
Peak hours: evenings are busiest, especially on mobile networks and shared fibre.
VPNs and proxies add distance and encryption overhead.
Very fast plans: above roughly 1 Gbps, the browser and device can become the limit rather than the line.

FAQ

Frequently asked questions

How accurate is this speed test?

It uses the same method as Cloudflare’s own test: precise browser timings, server time removed, and the 90th-percentile speed of many transfers. Results from different test sites differ a little because they use different servers and methods.

How much data does a speed test use?

It depends on your speed: a full test uses up to a few hundred MB on a very fast line, less on slower ones. Data saver mode uses at most about 39 MB — the page shows the exact amount after each test.

What is a good ping for gaming?

Under 30 ms is excellent and under 60 ms is good for most online games; jitter should stay below about 10–20 ms. Above 100 ms you will notice lag in fast-paced games.

What is the difference between Mbps and MB/s?

Speeds are quoted in megabits per second (Mbps); file sizes in megabytes. One byte is 8 bits, so 100 Mbps downloads about 12.5 MB per second.

Is the speed test private?

The test connects your browser to Cloudflare’s speed test servers, which see your IP address like any website does. JustTools doesn’t receive or store your results; your history stays in your browser.

Why is upload slower than download?

Most home and mobile plans are asymmetric — designed to receive more than they send. Fibre plans are often symmetric, so similar upload and download speeds are normal there.

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