What it is

ntfy is an HTTP-based publish-subscribe notification service that delivers push notifications to phones and desktops via simple REST API calls. It operates in the open-source notification ecosystem, providing a lightweight alternative to proprietary push notification infrastructure. Users publish messages to topics via standard HTTP methods, and subscribers receive them instantly on registered devices.

The service solves the problem of needing a reliable, low-latency, and dependency-free way to send alerts from scripts, servers, or applications to personal devices—without requiring user accounts, API keys, or payment for basic use. It replaces custom webhook setups or expensive third-party services for personal or internal tooling.

Key capabilities

• Publish notifications via HTTP PUT/POST to topic endpoints (e.g., PUT /ntfy/mytopic)
• Subscribe via HTTP long-polling, Server-Sent Events (SSE), or WebSockets
• Support for message priority levels (min, low, default, high, max)
• Attach files up to 5 MB via multipart form data or base64 encoding
• Topic access control via password protection or public/unlisted visibility
• Built-in authentication via tokens, basic auth, or OAuth2 (self-hosted instances)
• Cross-platform mobile apps (Android, iOS) and desktop clients for subscription

Who uses it and how

• DevOps engineers use it to send CI/CD pipeline alerts (e.g., build failures, deployments) directly to phones
• Home automation users trigger notifications from scripts (e.g., “Door opened”, “Backup complete”)
• Developers integrate ntfy into monitoring tools (e.g., Prometheus alertmanager, cron jobs) for real-time alerts

Getting started

Install via Docker (docker run -p 8080:8080 ntfysh/ntfy) or use the hosted service at ntfy.sh. Subscribe via the Android or iOS app, or use curl to publish: curl -d "Hello world" ntfy.sh/mytopic.

When to use it — and when not to

Use ntfy for lightweight, self-contained notification needs where simplicity and zero-cost operation matter more than enterprise SLAs. Avoid it if you require guaranteed delivery, message persistence beyond recent history, or complex routing logic—its pub-sub model is fire-and-forget with no built-in retry or queuing. Self-hosting requires managing TLS, storage, and optionally SMTP for email fallback, but no external database is needed. The free tier (ntfy.sh) has rate limits and no SLA; paid Pro plans offer higher limits and priority support.