About the Website Checker
“Is it down or just me?” deserves a better answer than a green checkmark. This checker runs the connection the way connections actually happen — DNS, then TCP, then the TLS handshake, then HTTP — from our network, and reports each layer’s pass/fail and timing separately. The failing layer names the culprit: dead DNS is a domain problem, refused TCP is an outage, a failed handshake is an expired certificate everyone will hit, a 503 is the application burning while the servers run fine.
And when every layer passes from here, you get the genuinely useful verdict: the problem is probably on your end — with the triage list that actually fixes it.
- Different network test: load it on your phone with Wi-Fi OFF. Works? Your network/computer is the problem.
- Flush DNS: Windows
ipconfig /flushdns· macOSsudo dscacheutil -flushcache— or switch resolver to 1.1.1.1 / 8.8.8.8. - Kill the middlemen: VPN, proxy, and browser extensions (try a private window).
- Hard refresh: Ctrl/Cmd+Shift+R beats a poisoned cache.
- Still stuck? Your ISP may have a routing issue to this host — it happens, and it passes.
Waiting out an outage? Recheck automatically every 30 seconds and log each result — the timeline is your incident note.
How to Use the Website Checker
Type the domain and check. The request runs from our server — a different network, resolver and route than yours — and walks the same four layers your browser walks: name resolution, the TCP connection, the TLS handshake, and the HTTP request itself. Each layer reports separately with its timing, and the verdict at the top translates the pattern into the sentence you actually need.
Reading the Layers Like an SRE
DNS fails: the domain expired, the nameservers are down, or a DNS change went wrong — nothing after this can work, for anyone. TCP fails: the machine or its network is gone; firewalls produce the same symptom. TLS fails: the server is alive but the certificate is expired, misissued or doesn’t cover the hostname — every browser on earth will refuse it, which is why cert expiry is the classic self-inflicted outage. HTTP 5xx: the web server relayed your request to an application that is currently on fire; 503s during big launches are this. Everything passes: now the interesting question is your machine — and the triage list on the result handles it.
Related tools: the DNS Lookup to inspect the records when layer one is the story, the SSL Certificate Checker for the full chain when layer three is, and the HTTP Security Grader for the headers once it’s back up. Browse every Dev & Tech tool for more.
One vantage point, honestly labelled: “up from our network” is strong evidence, not a global guarantee — regional outages and geo-blocks exist. Checks are cached 60 seconds per URL, redirects reported but not followed, and private/internal addresses refused by design.
Frequently Asked Questions
How does this decide "down" versus "just you"?
The check runs from our server, on a different network, different DNS resolver and different route than yours. If every layer passes from here — the name resolves, the server accepts a connection, the certificate verifies, HTTP answers — then the site is up in the general sense, and a failure in your browser points at something local: your DNS cache, your VPN or proxy, your ISP, or the site geo-blocking your region. If layers fail from here too, it is down for more than you.
What do the four layers mean?
They are the order every connection actually happens in, and each failure has a different culprit. DNS failing means the hostname no longer resolves — expired domain or broken DNS provider. TCP failing means nothing is listening — server crash, network outage or firewall. TLS failing means the machine is up but its certificate is expired or wrong, so browsers will refuse it for everyone. HTTP 5xx means the web server answered but the application behind it is broken. The tool stops blaming "the internet" and names the layer.
Why does it say up when I get an error?
The usual suspects, in observed frequency order: your DNS cache still holds an old IP (flush it, or try your phone on cellular data); a VPN or corporate proxy is interfering; your ISP has a routing problem to that host; the site blocks your country or your IP range; or an ad-blocker/extension is breaking one specific site. The fastest triage is exactly the "different network" test this page performs — if it loads from here and from your phone on cellular, your computer or network is the story.
Does a 404 mean the site is down?
No — a 404 is the server working correctly and telling you that specific path does not exist. The verdict treats 4xx as "up" for exactly that reason (with 429 flagged separately as rate-limiting). Down is 5xx — the application failing — or the layers beneath HTTP not answering at all.
Are the checks live?
Each result is fetched live and cached for 60 seconds per URL — fresh enough for outage-watching, while keeping a page full of people checking the same big-name outage from hammering the target. Redirects are reported but deliberately not followed: the first hop's answer is the diagnostic. And the checker refuses private and internal addresses outright — it looks at the public internet only.
