How much RAM does ntfy need? We measured: 27 MB idle
ntfy (pub-sub push notifications) used 27 MB of RAM across 1 process sitting idle with default configuration — measured by us, on real hardware, not copied from another blog. Runtime: Single Go binary (SQLite message cache)
27 MB. You can run ntfy, Gotify and File Browser together and still be under 70 MB of application memory.
What the vendors say
ntfy's own docs are refreshingly direct about being tiny. Hosting guides nonetheless suggest 1 GB instances.
What changes under load
Like Gotify, cost scales with concurrent subscribers rather than with time. The message cache is on disk, not in RAM, so retention is cheap.
Methodology
Each app was started with its default configuration and an empty data directory, left to settle for 25–30 seconds, and confirmed alive with an HTTP request to its web interface. We then recorded the resident set size (RSS) of the app's entire process tree via ps. Apps were run directly on the host (no Docker), so numbers exclude container overhead (~10–30 MB with Docker).
A fresh minimal Ubuntu 24.04 VPS typically idles at roughly 200–300 MB RSS (kernel, systemd, sshd, journald). All 'fits on' verdicts below assume ~300 MB reserved for the OS.
Where to run it
A 512 MB instance from Hetzner, Vultr or DigitalOcean covers this app with the OS overhead included. Don't pay for RAM the measurements say you won't use.
Other apps we measured
File Browser (16 MB), Gotify (20 MB), PocketBase (31 MB), Caddy (40 MB), Navidrome (47 MB), Syncthing (57 MB), Prometheus (70 MB), MinIO (132 MB), Uptime Kuma (136 MB), Gitea (158 MB), Forgejo (173 MB), code-server (VS Code in the browser) (191 MB)