Fly.io Performance Benchmarks (2026)

A repeatable method matters more than an impressive result. Whoever measured Fly.io, including you, should be able to say what data was used, how large it was, how many times the test ran, and what varied between runs; strip any of that away and two people will get two different numbers and both will be right. So rather than reconciling published figures, set up one small honest test of your own: realistic data, repeated runs, and a note of anything else the machine was doing. It will disagree with the marketing sometimes, and it will be correct.

Speed for a hosting & deployment product is felt rather than measured: the delay between asking and getting something usable is what shapes whether you keep using Fly.io. Test it on your largest realistic case rather than a small sample, because most tools feel fast until the data grows.

The failure you should worry about is the quiet one. Anything you depend on will eventually break; the question for Fly.io is whether it tells you, a visible error, an obvious retry, or lets bad state pass silently as though nothing happened. Check whether work in progress survives an interruption, and whether the vendor keeps an incident history you can actually read, because a documented outage record is a better trust signal than a spotless page with no history at all.

What Fly.io costs you in machine terms, memory, processing, storage, bandwidth, only becomes visible at scale or on modest hardware. If you are running it alongside a full working set of other tools, or on an older machine, check that footprint before committing rather than after.

Published comparisons are written against someone else's requirements, which is why they so often disagree with each other. Rebuild the hosting & deployment comparison around your own material instead: the same real task, the same volume, run through each contender in turn. Give Fly.io the cloud-infrastructure and paas work it is built for, and give every rival exactly the same job, since a fair test is the only kind worth running. Note where each one made you stop and think, because that hesitation is the cost you will pay repeatedly, and it never shows up in a table of ticks.