The Access Check tool helps you find out why a site won't open — from your own perspective, from inside Iran, and (when needed) from outside.
It combines checks from your browser, an Iran-based probe, and optionally an external probe and a full multi-provider DNS sweep. When you need to go deeper, it can also download a small local diagnostic script that runs on your own computer.
1. Enter a URL (e.g., `example.com` or `https://example.com/path`) 2. Click "Run Diagnostic" 3. Review the results
Optionally, check “Also run an advanced local diagnostic” to download a script you can inspect before running.
| Layer | What It Tests |
|---|---|
| Your browser | Whether your browser can reach the site directly |
| Iran probe (atrin01) | Whether the site is reachable from inside Iran |
| External probe | Whether the site is reachable from outside Iran (only if something looks wrong) |
| DNS sweep | Resolution across multiple DNS providers (only if something looks wrong) |
| Local diagnostic | Your DNS servers, proxy settings, ping, traceroute, and trusted root certificates |
To keep the common case cheap, the tool runs checks in stages:
This means a healthy site costs very little to check, and only a broken one triggers the deeper (and more expensive) investigations.
When you check the box, Access Check downloads a small script to your computer. You can read it before running it — it is plain text.
What the script does:
What it does not do:
The script writes a single file on your own computer. You choose whether to attach that file back into Access Check, where it is read entirely inside your own browser — it is never uploaded.
Many “site is down” problems are actually local — a wrong DNS server, a proxy misconfiguration, a system clock that's off, or a missing root certificate. Access Check separates local problems from real network or server problems.
For example:
tool accesscheck diagnostics iran