UptimeRobot Returns 405 but Your Website Works: Check HEAD vs GET

If UptimeRobot reports 405 Method Not Allowed while the same URL opens in your browser, compare its HEAD and GET responses before changing security rules. A browser usually loads the page with GET; an automated check may send HEAD. If HEAD returns 405 but GET returns 200, investigate method support and configure a suitable GET check. If GET also fails, switching methods alone is not the fix.

UptimeRobot · HTTP 405Website / API monitoringLast reviewed Oct 14, 2026

You are likely in the right place if:

Your monitor records HTTP 405, not a DNS or TLS timeout.The exact monitored URL appears to work in a browser.You need to distinguish request-method handling from a genuine application failure.

Choose your path after testing the same URL

HEAD 405 / GET 200Check the GET response is the intended page; then review monitor method or application HEAD support.

HEAD 405 / GET 405Inspect the endpoint contract and Allow header. Do not assume GET is supported.

Local GET works / monitor still failsCompare monitor URL, redirects, authentication and the provider's recorded request.

GET 200 / error contentStatus-only monitoring is passing the wrong content. Add a meaningful content assertion where appropriate.

First check: confirm the exact URL and HTTP method

Open the incident details. Record the time, status, monitored scheme, hostname and path. Then open that exact URL in a private browser window. A logged-in browser may succeed because it carries cookies the monitor does not have.

In UptimeRobot, open the HTTP/S monitor, choose Edit → Advanced Settings → HTTP Method, and note the saved method. Labels and availability may depend on the current interface and plan.

Verify: compare an identical target, not the homepage versus a different health endpoint. Keep the existing settings until you have the result of the next test.

Did the first check identify the mismatch?

Compare HEAD and GET without changing the server

Run the following against a public URL you own or are authorized to test. Replace example.com with the exact monitored hostname and path. These commands make one request each; they do not change configuration.

On Windows PowerShell, use curl.exe instead of curl to avoid the Windows PowerShell alias. On macOS/Linux, use curl. Do not include private tokens in shared commands.

HEAD — macOS/Linux:

curl -I --max-time 15 https://example.com/

GET — macOS/Linux:

curl -sS -D - -o /dev/null --max-time 15 https://example.com/

HEAD — Windows:

curl.exe -I --max-time 15 https://example.com/

For Windows, the GET equivalent is:

curl.exe -sS -D - -o NUL --max-time 15 https://example.com/

These first checks do not follow redirects. If you receive a 3xx, inspect Location and compare the intended final URL separately. A redirect response is not proof the destination is healthy. Do not use -X HEAD in place of -I.

Verify: retain both status lines and relevant headers, especially Allow and Location. A command producing headers does not establish that the application task works.

Recorded lab: one endpoint, two different results

On October 14, 2026, ErrorHarbor ran a Python HTTP fixture on loopback with curl. The route deliberately supported GET and rejected HEAD. These are excerpts of the captured results:

HEAD / → 405

Method rejected
Allow: GET

GET / → 200

Request succeeds
Content-Length: 13

Failure control

GET /down → 503
The failed HTTP response remains visible when using GET.

Recorded local HTTP results, presented as a responsive comparison. This fixture did not test a real monitor or its alert delivery.

HEAD /
HTTP/1.1 405 Method Not Allowed
Allow: GET

GET /
HTTP/1.1 200 OK
Content-Type: text/plain

GET /down
HTTP/1.1 503 Service Unavailable

The comparison demonstrates a method-specific failure, not a provider bug. The failure control confirms curl receives a 503 from this fixture over GET. It does not prove that an uptime service detects the failure or delivers an alert; those require the separate monitor verification below. The fixture used Python 3.12.14; it did not test real UptimeRobot retry behavior, a live firewall, Cloudflare or the Windows command. Lab source and recorded output are available for inspection.

Why the browser and uptime monitor can disagree

HTTP 405 means the target does not support the request method. An application route or security policy can handle HEAD differently from GET. The response should include an Allow header listing supported methods; missing or unexpected headers are useful evidence for the operator, not a reason to guess.

UptimeRobot's current documentation describes HEAD as the HTTP-monitor default with a possible GET retry. A HEAD failure therefore does not automatically mean its fallback failed. Compare the incident details and server logs with the saved configuration. Avoid relying on old advice that every monitor always sends only HEAD.

If HEAD fails but GET works, choose the right correction

Option A: monitor the public page with GET. If the intended check is public-page availability and the GET response is correct, set the monitor to GET where the interface permits. Preserve the old method, target, accepted statuses and redirect setting so the change can be reversed.

Option B: repair HEAD handling. If the endpoint is intended to support HEAD, ask the application or proxy administrator to correct the specific route. This may be preferable for health checks that intentionally avoid downloading a response body. Do not add permissive rules across every endpoint.

Verify: check several subsequent results, inspect the requested method in authorized logs where available, and repeat the original URL test. Then use an isolated staging failure to confirm the monitor still alerts on a genuine failure. Never interrupt production just to test an alert.

If GET also fails or the monitor still reports 405

Both methods return 405

Inspect Allow and the endpoint's documented methods. A POST-only API should not be treated as a public GET page. Choose a safe documented health endpoint or correctly configured API check.

Local GET succeeds, remote check fails

Ask the operator to correlate method, path, time and monitor source with access/security logs. Check authentication and routing differences before changing firewall rules. User-Agent alone is not a strong trust boundary.

GET returns 200 but shows a login or error page

The target is answering, but may not be fulfilling the task. Inspect the body privately and consider an expected-content check. A keyword assertion on HTML does not validate a complete checkout or execute client-side JavaScript.

Do not silence the symptom

Do not accept 405 as healthy merely to turn the dashboard green.Do not disable your firewall, WAF or HTTPS verification globally.Do not switch to a favicon and claim the application's critical action is monitored.Do not send production POST/PUT/DELETE requests as diagnostic experiments.

Still failing? Send evidence, not a guessed cause

Capture before contacting support:Exact URL, incident time/timezone and monitor type.Saved method, redirects and expected response settings.HEAD and GET results, Allow/Location headers and whether private browsing works.Sanitized access/security log entries matching the monitor request.Recent route, proxy or security changes.

Verify: after an approved correction, test both reachability and the original page's purpose. Record the change and whether the error recurs from the monitor's location.

Optional: configure an explicit GET check in Better Stack

If your existing monitor supports the needed method and validates the right target, you can keep it. Switching services is not required to fix a method mismatch.

For a new monitoring setup, Better Stack documents GET as the default and method customization under Monitors → select monitor → Configure → Advanced settings → Request parameters. Confirm the target, redirects and authentication before enabling alerts. We verified the documentation, not a signed-in Better Stack setup.

Affiliate disclosure: ErrorHarbor may earn a commission if you purchase through the following link, at no additional cost to you. The free diagnosis above does not require a purchase.

Explore Better Stack monitoring or read its request configuration documentation first.

Official references

Still stuck? Ask the community

Share your monitor type, exact status code, sanitized URL pattern and HEAD/GET comparison. Do not post private URLs or authorization headers.

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