What does it really cost to host a small app?

Cheapest that never sleeps: Northflank, free up to 1 GB (Sandbox tier: 2 services, up to $20/mo of resources).

Cheapest you pay for: Fly.io, at every size here — $2.19 a month for 256 MB, $13.39 for 2 GB.

Heroku's price climbs fastest: $7.00 for 512 MB, $50.00 for 1 GB, $250.00 for 2 GB.

Render has no 1 GB size — at 1 GB you pay for Standard, 2 GB, $25.00 a month.

Heroku has no 2 GB size — at 2 GB you pay for Performance-M, 2.5 GB, $250.00 a month.

• Most apps also need a database, and it is often the bigger bill. Fly.io's own worked example: a small app at $3.69 a month next to Managed Postgres at $38.00.
• A free tier has limits. Northflank's Sandbox covers 2 services, 2 jobs and 1 database, up to $20 a month of resources; past that you are on pay as you go.
• Usage billing moves with your traffic. Fly.io and Railway bill by the second; a busy month costs more than the figures here, a quiet one less.
• Bandwidth is not counted. Each platform includes some and charges for more.

Read this page as the cost floor for one small service, not the answer for your whole stack.

An AI agent read each platform's pricing page in a real browser and copied the sentence behind every figure; code checked each sentence was really on the page before it could be used.

A disclosure: Alan, who publishes this, runs his own product on Fly.io. It comes out as the cheapest paid option at every size here, which is a reason to check the sums rather than take them on trust — every row below links to the vendor's own page. There are no affiliate links on this page and nothing on it earns a commission.

monthly cost = the cheapest option that never sleeps with at least that much memory + any plan fee

Each figure is the plan named under it. Where a platform has no plan at a size, the next size up is used and named.

Railway. Railway bills the memory and CPU you actually use, by the second. Assumed: the app holds its full memory all month and averages 5% of one vCPU. Memory $0.00000386 per GB-second is $10.01 per GB over a 30-day month; CPU $0.00000772 per vCPU-second is $20.01 per vCPU, so 5% of one is $1.00. The Hobby plan's $5 minimum includes $5 of that usage.

Left out: Render free instance — Render's own table lists it as "Free ( limitations apply )" without saying it stays on, so it is left out of an always-on comparison; Heroku Eco ($5) — Heroku's own table: "Sleeps after 30 minutes of inactivity"; Koyeb — its page does not make clear what the free instance includes, so it is left out rather than guessed at.