Free tools Windows power users keep installed
One-click scans. No signup required.
A reliable curl monitor is a small shell program that makes one bounded HTTP request, checks explicit health rules, records status and timing, and exits nonzero when the site fails. A scheduler such as cron can run it every few minutes, while cron mail, a paging wrapper, or a heartbeat service turns that exit code into an alert.
What a curl website monitor should check
“Curl returned output” is not a health check. Define success before writing the command:
- The request connects before a connection deadline.
- The complete operation finishes before a total deadline.
- The final HTTP status, after any intended redirects, is accepted.
- The response time is below your service-level threshold.
- For a deterministic health endpoint, the body contains an invariant marker.
- TLS certificate validation remains enabled.
Use a small /health or /ready endpoint when possible. Avoid exact-string tests on personalized home pages, where content changes by cookie, location, or account.
A production-ready POSIX shell script
Save this as /usr/local/bin/check-site.sh and make it executable with chmod 755 /usr/local/bin/check-site.sh:
#1 Best Overall
- Includes Raspberry Pi 5 with 2.4Ghz 64-bit quad-core CPU (8GB RAM)
- Includes 128GB Micro SD Card pre-loaded with 64-bit Raspberry Pi OS, USB MicroSD Card Reader
- CanaKit Turbine Black Case for the Raspberry Pi 5
- CanaKit Low Noise Bearing System Fan
- Mega Heat Sink - Black Anodized
#!/usr/bin/env sh
set -eu
url="https://example.com/health"
max_time=15
tmp="$(mktemp)"
trap 'rm -f "$tmp"' EXIT
result=$(curl --silent --show-error --location
--connect-timeout 5 --max-time "$max_time"
--output "$tmp"
--write-out '%{http_code} %{time_total}'
"$url") || {
printf '%s transport failure: %sn' "$(date -u +%FT%TZ)" "$url" >&2
exit 1
}
http_code=${result% *}
time_total=${result#* }
if [ "$http_code" -lt 200 ] || [ "$http_code" -ge 400 ]; then
printf '%s HTTP %s in %ss: %sn' "$(date -u +%FT%TZ)" "$http_code" "$time_total" "$url" >&2
exit 1
fi
printf '%s OK HTTP %s in %ss: %sn' "$(date -u +%FT%TZ)" "$http_code" "$time_total" "$url"
The script follows redirects, stores the body in a temporary file instead of printing it, and emits the final status and total duration. A DNS error, refused connection, TLS failure, or timeout enters the transport-failure branch. A 404 or 500 produces an HTTP failure with its status visible to operators.
Adding a body-marker test
Only add this for stable, non-personalized content. For example, after parsing time_total, add:
if ! grep -Fq 'status: ok' "$tmp"; then
printf '%s body marker missing: %sn' "$(date -u +%FT%TZ)" "$url" >&2
exit 1
fiDo not put passwords, authorization headers, or response bodies into ordinary logs. Keep credentials in protected environment variables or a secret manager and send only the minimum headers required.
HEAD or GET: choose deliberately
Use HEAD for a cheap availability check
curl --head https://example.com asks for headers only, so it avoids downloading the response body. It is efficient for servers that implement HEAD correctly.
Use GET when content matters
Some servers deny HEAD while allowing GET. Use the script’s GET request when you need to verify a marker, exercise application code, or support endpoints with incomplete HEAD implementations. Keep --output pointed at a file so a large page does not flood a terminal or cron mail.
Rank #2
- Includes Raspberry Pi 4 4GB Model B with 1.5GHz 64-bit quad-core CPU (4GB RAM)
- Includes Pre-Loaded 32GB EVO+ Micro SD Card (Class 10), USB MicroSD Card Reader
- CanaKit Premium High-Gloss Raspberry Pi 4 Case with Integrated Fan Mount, CanaKit Low Noise Bearing System Fan
- CanaKit 3.5A USB-C Raspberry Pi 4 Power Supply (US Plug) with Noise Filter, Set of Heat Sinks, Display Cable - 6 foot (Supports up to 4K60p)
- CanaKit USB-C PiSwitch (On/Off Power Switch for Raspberry Pi 4)
Redirect behavior
--location follows redirects and reports the final response. Keep it when the destination is part of the intended check; remove it when a redirect itself indicates misconfiguration. Always decide whether HTTP-to-HTTPS redirects, login redirects, and cross-host redirects are success or failure for your service.
Timeouts, slow transfers, and curl exit codes
--connect-timeout 5 bounds connection establishment. --max-time 15 bounds the entire request, including redirects and body transfer. Set both: a connection can succeed while an application hangs indefinitely.
For endpoints that trickle data too slowly, add a transfer-rate guard:
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
curl --silent --show-error --location
--connect-timeout 5 --max-time 30
--speed-limit 1024 --speed-time 10
--output /tmp/health-body "$url"The speed options abort a transfer that remains below the chosen rate for the chosen interval. Tune them to your endpoint rather than applying them to every download.
--fail makes HTTP responses outside curl’s success range fail the command and suppresses the body. It is useful for one-off checks, but a monitor should still capture %{http_code}; distinguishing a 404 from DNS, TLS, and timeout failures makes remediation faster. The script above therefore evaluates the status explicitly instead of relying only on --fail.
Rank #3
- Not including the Raspberry Pi 5 (8GB), the Crowpi advanced version comes with the Raspberry Pi 5
- ELECROW Black Case for the Raspberry Pi 5, CrowPi is equipped with a 9-inch HD touchscreen along with a camera; All the regular components used in DIY electronics are packed into the CrowPi development board, such as LCD, LED matrix, buzzer, light sensor, PIR sensor, ultrasonic sensor, IR sensor, etc
- Raspberry Pi Sensors: The Crowpi raspberry pi 5 programming kit is jam-packed with lots of buttons such as 19 different sensors in a tidy easy to use package; You don't have to wait and wire things
- Build Quality: Solid ABS shell and well made components in one place make it strong and convenient to travel
- Programming Lessons: This raspberry pi 5 learning kit ships with step by step instructions and provides 21 lessons to take you through identifying components reading code and running it in the terminal
Logging useful evidence
Log UTC timestamp, URL or check name, final status, elapsed time, and a failure class. A compact success line looks like:
2026-09-30T12:00:00Z OK HTTP 200 in 0.184s: https://example.com/healthRotate logs or send them to your system journal. Never log query strings or headers that contain tokens. If a check has warning and critical latency thresholds, keep those thresholds separate from the hard timeout: a 2-second warning can identify degradation while a 15-second timeout determines outright failure.
Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallRun the check from cron
Install this crontab entry with crontab -e:
*/5 * * * * /usr/local/bin/check-site.sh >>/var/log/check-site.log 2>&1Cron runs with a limited environment. Use absolute paths, set any required environment variables in a protected file, and verify that the cron user can execute curl, write the log, and create temporary files.
Making failures alert someone
- Cron can email command output when configured on the host.
- A wrapper can send a notification only when the script exits nonzero.
- A heartbeat endpoint can receive a success ping; missing pings then trigger an alert.
- A systemd timer can replace cron when you need service dependencies, journal integration, or randomized scheduling.
Test the failure path intentionally with a disposable URL or a deliberately blocked port. Confirm that the command exits 1, produces a useful line, and reaches the alert channel.
Local script or hosted monitoring?
| Consideration | Local curl script | Hosted monitor |
|---|---|---|
| Detection | HEAD or GET rules you control | Provider-defined HTTP checks and options |
| Scheduling | Your cron or systemd timer | Provider-managed schedule |
| vantage points | Usually one machine and network | May run from independent external locations |
| History | Your log retention | Often includes retained check history |
| Alerts | You build mail, paging, or heartbeat integration | Notification routing is typically built in |
| Cost and control | Transparent and inexpensive; you operate it | Operational features in exchange for service dependency and subscription cost |
A local check can miss an outage that affects only users outside your network. A hosted check cannot validate private localhost services unless you provide a secure reachable endpoint or an agent. Compare authentication support, redirect and TLS controls, latency thresholds, log retention, and alert behavior before moving.
Rank #4
- Fully assembled for plug-and-play operation
- Includes Raspberry Pi 5 with 8GB RAM
- 256 GB PCIe Pi NVMe SSD (Pre-loaded with Pi 64-Bit OS)
- M.2 HAT+
- CanaKit Turbine Black Case for the Pi 5
Troubleshooting common failures
HTTP 404, 401, or 500
Inspect the final URL and status. A 401 may be expected for a protected endpoint; configure the minimum required authentication rather than marking every 4xx as healthy. A 500 usually indicates an application or upstream failure. Adjust the accepted range only when the endpoint contract explicitly allows it.
Recommended Free Tools
HEAD returns 405 or 403
Switch to GET with --output. Do not treat a rejected HEAD as proof that the site is down.
Timeouts
Use verbose mode on a manual run to identify DNS, connection, TLS, redirect, or transfer delay:
curl --verbose --connect-timeout 5 --max-time 15 https://example.com/healthKeep certificate verification enabled. Increasing the timeout can hide a regression; first determine which phase is slow.
Redirect loops or unexpected login pages
Run without --location to inspect the first response, then decide whether the redirect target is part of the check. Authenticated checks should use a dedicated health endpoint, not an interactive login flow.
Best Value
- 【What you Get】You will get 1*Pi 5 8GB Single Board,1*RasTech Case,1*Active Cooler,1*Screwdriver,1*Installation instructions,12-month free warranty, lifetime service, 24-hour prompt and friendly response.
- 【More Connectors】There are two USB 3.0 ports(5Gbps simultaneously) and two USB 2.0 ports, which triple total bandwidth ,support any combination of up to two cameras or displays. Peak SD card performance is doubled through support for the SDR104 high-speed mode. It provides a smooth desktop experience for you. Offer Gigabit Ethernet and a PCIe interface, along with dual-band Wi-Fi and Bluetooth 5.0/BLE wireless capability. The RasTech Pi 5 Kit use the new 27W 5.1V 5A USB-C power connector.
- 【 Support Dual 4Kp60 Display 】Each of the two microHDMI sockets can control a 4K display at 60 Hertz, now support HDR, offering super HD video for media streaming projects. RPi 5 is the first RPi model that comes with a PCI Express port (PCIe 2.0 x1 with 500 MB/s) to attach SSDs (requires separate M.2 HAT).
- 【 Excellent Chips And Applications】Pi 5 is a full-size Pi computer using silicon built in-house at Pi. The RP1 “southbridge” provides the bulk of the I/O capabilities for Pi 5. Pi 5 is more friendly and convenient in the development of Internet of Things, Web development, machine identification, automatic control and other electronic equipment applications and network.
- 【 Faster CPU, Better GPU 】 Pi 5 features a Broadcom BCM2712 64-bit quad-core Arm Cortex-A76 processor running at 2.4GHz, it delivers a 2–3× increase in CPU performance relative to RaspberryPi 4. The 800MHz VideoCore VII GPU is compatible to OpenGL ES 3.1 and Vulkan 1.2, substantial uplift in graphics performance. Pi 5 Offers lightning-fast CPU speed, a PCI Express interface, a Real Time Clock (RTC) and a power button and runs significantly cooler than Pi 4.
Works interactively but fails in cron
Check absolute command paths, file permissions, working-directory assumptions, proxy variables, DNS configuration, and the cron user’s certificate store. Capture stderr in the cron log while diagnosing, then remove sensitive details.
Or skip the browser setup
If your goal is a screenshot-based check or visual record rather than a raw HTTP health probe, ScreenshotNeo provides a single GET request and an MCP server for AI agents. Before capture it accepts cookie or consent banners and removes more than 60 known consent platforms, newsletter popups, and chat widgets; each cleanup step can be disabled. Bot checks or CAPTCHAs, blank pages, timeouts, failed loads, and cache hits are not billed, and the response identifies the page verdict and billing result in headers.
See the ScreenshotNeo API documentation for all options. A curl call is:
curl -G "https://api.screenshotneo.com/v1/shot" -d access_key=YOUR_API_KEY --data-urlencode url=https://stripe.com -o shot.webpYou can also use Python:
import requests
r = requests.get("https://api.screenshotneo.com/v1/shot", params={"access_key": "YOUR_API_KEY", "url": "https://stripe.com"}, timeout=90)
open("shot.webp", "wb").write(r.content)Or Node.js:
const q = new URLSearchParams({ access_key: 'YOUR_API_KEY', url: 'https://stripe.com' });
const res = await fetch(`https://api.screenshotneo.com/v1/shot?${q}`);ScreenshotNeo supports full-page and element captures, device and viewport settings, dark mode, retina scale, PDFs, custom CSS or JavaScript, clicks, waits, request blocking, headers, cookies, user agents, timezone and geolocation, caching, signed links, asynchronous jobs, bulk capture, usage reporting, and an OpenAPI specification. Its MCP tools are take_screenshot, get_page_info, and capture_pdf. The free plan includes 1,000 screenshots per month without a card; paid plans start at $5 for 3,000. Create a free ScreenshotNeo account.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Practical checklist
- Use a deterministic health endpoint.
- Set both connection and total-operation timeouts.
- Choose HEAD or GET based on server support and validation needs.
- Follow redirects only when the final destination is intended.
- Record status, duration, timestamp, and failure class.
- Keep secrets out of command lines and logs where possible.
- Make every failed condition exit nonzero.
- Test cron and alert delivery with an intentional failure.
- Move to external monitoring when you need independent locations, history, or managed notification workflows.
Frequently Asked Questions
Should I monitor a homepage or a health endpoint?
Prefer a small deterministic health endpoint; homepages often vary by cookie, account, and location.
What does a nonzero exit status mean?
It tells cron or an alert wrapper that a transport, timeout, HTTP-status, latency, or content rule failed.
Can curl verify TLS certificates?
Yes. Its normal certificate verification should remain enabled; investigate certificate failures instead of disabling verification.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
