Keeping one small app running all month costs anything from nothing to $250, depending on where you put it and how much memory it needs.
I asked for the arithmetic on six platforms — Fly.io, Northflank, DigitalOcean, Railway, Render and Heroku — for one web service that never sleeps, at 256 MB, 512 MB, 1 GB and 2 GB of memory. Each figure was read off the vendor's own pricing page and checked against the sentence it came from.
What came out
- Northflank's free Sandbox keeps an app always on up to 1 GB. It covers two services and up to $20 a month of resources, and its page says plainly: "Always on, no sleeping".
- Fly.io is the cheapest you pay for, at every size — $2.19 a month for 256 MB, $13.39 for 2 GB.
- Heroku climbs fastest: $7 at 512 MB, $50 at 1 GB, $250 once you need more than that.
- Render has no 1 GB size. Past 512 MB the next step is 2 GB at $25 a month.
A disclosure
I run my own product on Fly.io, and it comes out cheapest among the paid options. That is a reason to check the sums rather than take my word for them, so every row on the page links to the vendor's pricing page. There are no affiliate links on it.
What the table cannot tell you
The server is rarely the expensive part. Fly.io's own worked example puts a small app at $3.69 a month next to a managed Postgres database at $38. A free tier has limits that matter later. And platforms that bill by the second move with your traffic, so a busy month costs more than the figures here.
Free tiers that sleep when nobody is using them were left out on purpose. An app that takes ten seconds to wake up is a different product, and comparing it with one that is always on flatters the price.
For anyone building with agents, hosting has quietly become a recurring purchase decision. It deserves the same arithmetic as any other.
The page this is about: What does it really cost to host a small app? — every figure sourced to the vendor's own page, with the date it was checked.