How do I open a server and check whether it responds?
Open or copy a server's URL, choose its address and protocol, and enable optional HTTP readiness checks.
In this article
Open the server or copy its address
- Click Radar's menu bar icon.
- Click the text area of the server's card to open its selected URL in your Mac's default browser. You can also right-click the card and choose Open in Browser.
- To inspect or copy the URL, click the information button or right-click the card and choose Details….
- In Endpoints, use Copy URL to copy the full address, or Open to open it.
Opening Details closes the panel and opens a separate [project name] — Server Details window. The window can be resized, and its content scrolls. Opening another server's Details reuses this window.
If the card says Choose endpoint…, clicking its text opens Details so you can select an address. A listening TCP service is not necessarily an HTTP website. Choose HTTP or HTTPS only when that service actually speaks the selected protocol.
Choose the right Address and Protocol
- In the server's Details window, find Endpoints.
- Choose a listening address from Address. It includes the bound IP address and port.
- Set Protocol to HTTP or HTTPS.
- Check the URL below the pickers, then click Open or Copy URL.
Recognized tools automatically use the first available endpoint until you select one. The default protocol is HTTP. Services labeled Other require an explicit Address choice before a URL is available. For a recognized tool, Choose endpoint returns to automatic selection. For Other, it removes the explicit choice.
An address such as 0.0.0.0:3000 means the server bound a wildcard IPv4 address. Radar uses 127.0.0.1 in the URL so the browser can connect locally. A wildcard IPv6 address such as [::]:9443 becomes [::1] in the URL. A specific address is retained. IPv6 addresses appear in square brackets.
For example, selecting 0.0.0.0:3000 and HTTP produces http://127.0.0.1:3000. Selecting [::]:9443 and HTTPS produces https://[::1]:9443. These examples explain URL construction; they do not imply that a server supports HTTPS just because it uses a particular port.
Address, Protocol, and readiness choices are saved for the project folder. Other cards using that same folder share them. If a selected address later disappears, a recognized tool falls back to its first current endpoint. Other requires another explicit choice. See shared project preferences.
Use the optional HTTP readiness check
- Open Details and choose the intended Address and Protocol.
- Turn on Check HTTP readiness every 30 seconds.
- Wait for Checking… to change to an HTTP status or No HTTP response.
Readiness checks are off by default. They make a HEAD request to the selected base URL. They do not fetch a page body, use browser login cookies, send saved credentials, follow redirects, or bypass TLS validation. Any HTTP response proves that an HTTP endpoint responded; it does not prove that the application is healthy.
| Status | Meaning |
|---|---|
| Readiness checks are off | The project's readiness switch is off |
| Checking… | A check is pending or in progress; a fresh result is not yet available |
| HTTP 200, HTTP 204, or another HTTP code | Radar received that status from the selected endpoint |
| No HTTP response | Radar did not receive a usable HTTP response, including connection, timeout, or TLS failures |
Radar schedules checks on successful scans, at least 30 seconds apart for each server. A slower background scan interval can make checks less frequent. At most four checks run at once, so a busy list can delay a check. Changing project preferences clears the old readiness result and allows a fresh check. Sleep cancels active checks; waking starts observation again.
Understand failures, redirects and disabled controls
If Copy URL or readiness is disabled, select an Address first. Open is also disabled when that server is no longer in the monitored list.
If you see No HTTP response, check the Address and Protocol, then try the same URL in the browser. HTTPS certificate errors remain errors in Radar, even if you chose to bypass them in a browser. A database or other non-HTTP listener can appear in Radar without supporting either protocol.
HTTP 302 means the original endpoint returned a redirect. Radar reports that status and does not check the destination. HTTP 401, HTTP 404, or HTTP 500 still means an HTTP response arrived; inspect the application separately to understand the error.
If a Details window says Server stopped, reopen the panel to check current monitoring. The window retains its original details after the card disappears. A disappearance can also follow a detection change or an ignored project; it is not independent proof that the process exited.
See readiness troubleshooting for a fuller diagnostic procedure.