What should we check?
Check my device
IP, provider, speed and VPN leaks
Check this
Type a site, domain, IP or subnet
All tools
GuidesEvery CheckNet check has a guide: what it is, why it matters and how to fix it, step by step.My device
Your IP
…
Checks
Speed testDownload, upload and ping
Open port on my IPCan the outside reach your device or router?
My IP’s networkNetwork owner and reverse name
More details
This connection
This device
This is what Cloudflare sees of this connection. Nothing is stored.
Your request headers
Speed test
Measured to the nearest Cloudflare data centre, with no other service involved. On a fast connection it uses up to about 200 MB of data.
Ping–ms
Download–Mbps
Upload–Mbps
Megabits or megabytes? What are ping and jitter?
Providers sell speed in megabits per second, but browsers and download apps usually show megabytes per second. A byte is eight bits, so a 100 Mbps line downloads at about 12.5 MB/s at best.
Ping is the round-trip time of a small packet, and for games, video calls and pages opening quickly it matters more than download speed. Jitter is how much ping moves up and down; a lot of it makes voices break up in calls. This test measures to the nearest Cloudflare data centre, not to the site you use.
Is it blocked?
The site is opened from networks inside the country and from outside it, next to OONI’s figures for the last month.
Does it open everywhere?
We open the site from several countries, so you can see whether it is reachable everywhere.
Port check
Timed from the Cloudflare data centre nearest to you, not from your device. Common ports only.
Ping and route
Ping tells you how far away a host is; traceroute and MTR show the path hop by hop. It runs from places around the world, not from your device.
DNS
Domain records, DNS and email health, and DNS answers from around the world.
DNS answers from around the world
Domain info
Registrar, registration and expiry dates and name servers, from RDAP.
SSL certificate
Check a site’s certificate, or read a certificate (PEM).
Have a certificate (PEM)?
IP lookup
The network owner, country, abuse contact and reverse name (PTR) of an IP.
Encode and decode
Everything runs in this browser; nothing you type here is sent anywhere.
The signature is not checked; only the contents are shown.
Subnet calculator
Type an IP with a prefix or a mask, like 192.168.1.10/24, or a number to turn into an IP.
Speed units
Providers sell megabits per second; browsers show downloads in megabytes.
Guides
Every CheckNet check has a guide: what it is, why it matters and how to fix it, step by step.