In short
Both bill per second while your app runs. Fly.io prices a machine by its size whatever the load, which is cheap for small machines; Railway charges for the CPU actually used, so it does well with generous sizes and light load and worse when the CPU is busy. Fly's managed Postgres starts at $38 a month, while Railway runs Postgres as an ordinary service billed by usage.
Fly.io
- Machines billed per second while running; from 1 October 2026 the smallest (shared CPU, 256 MB) is $2.19 a month.
- No free allowance for new customers; the trial is 2 machine hours or 7 days.
- Egress $0.02 per GB in North America and Europe; a dedicated IPv4 address is $2 a month.
- Managed Postgres from $38 (1 GB) plus $0.28 per GB of storage.
- Volumes $0.15 per GB-month, one per machine; stopped machines pay $0.15 per GB of root filesystem.
Railway
- Usage-based: $20 per vCPU-month and $10 per GB-month of memory actually used, billed per second.
- Hobby costs $5 a month and includes $5 of usage; Pro costs $20 and includes $20.
- A free plan gives $1 of usage a month, capped at 1 vCPU and 0.5 GB of memory per service.
- Idle services can sleep and cost nothing while asleep; the next request wakes them.
- Egress $0.05 per GB from the first gigabyte; volumes $0.15 per GB-month, up to 5 GB on Hobby.
- Postgres runs as an ordinary service at the same rates. Replicas can't use volumes.
More comparisons
Sources
Prices were read from these pages on 29 September 2026.