My stack

    Fly.io reviews

    Usage-based platform for deploying containerized apps and databases across global regions, billed by the second instead of a flat subscription.

    Visit website
    ToolTrim verdict3.6/ 5Average

    Modeling a small workload against Fly's published per-second rates (from about $0.00000078/s per shared-CPU machine) before committing is worth it since there is no flat entry plan to compare against.

    Fly.io, preview 1
    About

    In practice. What you can do with Fly.io.

    Fly.io runs containerized applications as Fly Machines distributed across a global network of regions, close to end users, with managed Postgres, persistent volumes, and an optional managed Kubernetes control plane (Fly Kubernetes).

    There is no flat subscription: billing is entirely usage-based, pro-rated by the second, starting near zero for small workloads. A small set of free allowances (SSL certificates, snapshot storage, shared IPv4) offsets some early costs, but a credit card is required once usage grows, and total monthly cost depends on traffic rather than a fixed plan. It suits developers comfortable reading a usage-based rate card.

    Practical uses

    • Deploy a containerized side project or API worldwide without provisioning fixed servers, paying only for the seconds it runs.
    • Run a Postgres-backed appPersistent storage across regions using Fly Volumes and Managed Postgres.

    Features & use cases

    Deployment
    Devops
    Nocode web

    Pros and cons. What Fly.io does well, and what to expect.

    Pros

    • No base subscription fee; costs scale down to near zero for small or intermittent workloads.
    • Includes managed Postgres, persistent volumes, and an optional managed Kubernetes layer beyond plain container hosting.

    Cons

    • Total monthly cost is hard to predict without modeling actual traffic and storage use.
    • Deleting an app does not automatically delete its associated Managed Postgres database, a common source of surprise cost.

    When it makes sense. Keep Fly.io, or challenge it?

    Keep if

    • You're comfortable reading a usage-based rate card and want to pay only for compute you actually run, across global regions.

    Challenge if

    • You need a fixed, predictable monthly hosting bill without modeling traffic first.

    Our verdict. What to know about Fly.io.

    Why this verdict

    Average

    Added value

    Usage-based pricing with no base subscription fee scales down to near zero for small workloads, a real advantage over flat-rate PaaS plans, though total cost isn't fixed.

    Simplicity

    Neutral score: onboarding and time-to-first-deploy are not covered by the collected sources.

    Fit for purpose

    Deploys containerized Fly Machines across global regions as advertised, with managed Postgres and volumes for persistent storage.

    Performance

    Offers shared and performance-CPU compute tiers, managed Postgres, volumes, and a managed Kubernetes control plane (Fly Kubernetes), covering more than basic container hosting.

    Reversibility

    Neutral score: export/portability of Managed Postgres and Volumes is not covered by the collected sources.

    Fly.io
    Visit

    What’s next?