Uptime Transition Alert to Telegram

Check a website every five minutes and send a Telegram alert when its HTTP status changes between up and down.

Setup

Connect Telegram and set the chat ID in Send the Telegram alert. In Open Flow, set the target URL in Check the website and add the target hostname and every possible redirect hostname to that Code node’s HTTP capability allowlist (up to 20 host patterns). In n8n, set the URL in Chiama il sito, connect Telegram and set the chat ID. Run one format with persistent workflow state and avoid overlapping executions.

Behavior

Every five minutes, the workflow GETs the website, following up to 21 redirects within a ten-second total request budget. HTTP 5xx is down; other HTTP statuses are up. The first up check is silent. A transition to down sends a red alert; a subsequent transition back up sends a green alert. Repeated results send nothing. A network error or timeout stops the run without changing state or sending a status alert.

Both formats save a changed state after Telegram confirms the alert. A failed or uncertain send leaves the old state, so the next check tries the transition again. An uncertain send may have arrived and the retry can duplicate it; inspect the chat before manually retrying. Persistent state is scoped to the workflow, so use a separate workflow for each website. In Open Flow an unlisted redirect hostname or an HTTP response larger than 1 MiB stops the run without changing state.

Inspiration & credits

Changes to the source

• Replace the example URL and environment-variable chat ID with workflow configuration. Open Flow requires the HTTP host allowlist.
• Configure the n8n HTTP node to return the final status for non-2xx responses; the original flat option did not apply and the response did not include statusCode. Disable n8n’s automatic Telegram footer and save the changed state after a successful alert, so failed sends can be retried on the next check.

Adapted from Uptime Ping Alert — sai che un sito è giù prima dei tuoi utenti in enescingoz/awesome-n8n-templates.

Source collection notice: © 2024–2026 Enes Cingoz, CC BY 4.0. The source export does not identify a separate template author or license. See repository licensing for the scope of OOMOL contributions and third-party material.