Why test internet speed?
An internet speed test tells you whether you receive the speed you pay for, and whether your connection supports what you actually do, such as 4K streaming, video calls, gaming and cloud work.
無料かつプライベートなインターネット速度テスト
インターネット速度を測定する 今すぐ
ダウンロード、アップロード、ping、ジッター、パケットロスを数秒で測定し、わかりやすいインターネットフィットネススコアを算出します。
- No accounts, no tracking
- Full result in 30 seconds
- Internet Fitness Score
- Works worldwide
- 100% free, forever
Live diagnostics
Test your connection speed
Online
準備完了
サーバー: InternetSpeedTest.fit edgeダウンロード速度
—Mbps
What you receive (streaming and browsing)
アップロード速度
—Mbps
What you send (calls, backups, uploads)
Ping
—
ジッター
—
パケットロス
—
IP address
—
サーバー
InternetSpeedTest.fit edge
Connection
—
Provider
—
Test duration
—
Tests run against InternetSpeedTest.fit edge. Results stay in your browser, nothing is stored against an account. Read the methodology
Your Internet Fitness Score
Run a test to turn download, upload, ping, jitter and packet loss into one number you can act on.
Understand your connection
What your speed test results really mean
Short, practical explanations of every metric behind your Internet Fitness Score.
How often should I test?
Monthly for a healthy baseline, plus any time performance drops. Testing at peak evening hours exposes congestion daytime tests never reveal.
Understanding ping and latency
Ping is the round-trip time of a data packet in milliseconds. Under 30 ms feels instant; above 100 ms adds noticeable lag to video calls and competitive games.
Download vs upload speed
Download speed governs what you receive, such as streaming and browsing. Upload speed governs what you send, such as video calls, backups and large file transfers.
What affects internet speed?
Router age, WiFi interference, distance from the router, device limits, VPNs, background downloads and network congestion all reduce real-world throughput.
How to improve slow internet
Compare wired against wireless, restart the router, switch to the 5 GHz band, update firmware and re-test at different times before contacting your provider.
Related guides
Go deeper on internet performance
Plain-language explainers for the questions that come up after every speed test.
Fundamentals
What is Ping?
How latency is measured, what a good ping looks like and how to lower yours.
Fundamentals
What is Jitter?
Why unstable latency ruins calls and games even on a fast connection.
Troubleshooting
Why is my WiFi slow?
Interference, channel overlap, placement and the fixes that actually work.
Troubleshooting
How to improve internet speed
A practical checklist from router placement to DNS and firmware.
Use cases
Internet speed for gaming
The latency, jitter and bandwidth targets competitive play really needs.
Use cases
Best internet speed for Netflix
Bandwidth per stream for SD, HD and 4K, as well as how many streams your line handles.
Fundamentals
Mbps vs MB/s
The eight-times difference that explains why downloads look slower than your plan.
Connections
Fiber vs Broadband
Latency, symmetry and reliability compared across fibre, cable and DSL.
Latest from the blog
Original guides and deep dives on internet speed, WiFi, and home networking.
Fundamentals
Understanding your Internet Fitness Score
Speed alone never told the whole story. Here is how download, upload, ping, jitter and packet loss combine into one number you can act on.
Salman Syed · 8 min
Troubleshooting
How to fix slow WiFi in one evening
A methodical checklist that isolates whether the problem is your router, your channel or your provider.
Salman Syed · 9 min
Fundamentals
Ping, jitter and packet loss explained
The three stability metrics that decide whether calls and games feel smooth, regardless of your Mbps.
Salman Syed · 6 min
Connections
Fibre, cable and 5G compared
Symmetry, latency and peak-hour behaviour across the three connection types most homes can choose from.
Editorial Team · 7 min
Use cases
How much speed does a household really need?
Per-activity bandwidth budgets you can add up for your own home instead of guessing at a plan tier.
Salman Syed · 6 min
Fundamentals
Reading a speed test like an engineer
What the numbers hide, why results vary and how to run a test that is genuinely comparable over time.
Editorial Team · 7 min
Get internet tips that actually help
Practical, jargon-free guides on WiFi troubleshooting, speed test results, and home network optimisation — delivered to your inbox. No spam, unsubscribe anytime.
Free forever · No spam · Unsubscribe anytime
FAQ
Frequently asked questions
Answers to the questions people ask most about internet speed, latency and connection quality.