Fly.io vs Deno Deploy for Solo Developers

Quick Comparison

Fly.io Overview

Fly.io deploys Docker containers as Firecracker micro VMs on edge servers across the world. You get full control over your runtime environment. Any language, any framework, any system dependency. Configure your app in fly.toml, deploy via CLI, and your containers run close to users globally.

The platform includes managed Postgres, persistent volumes, private networking between services, and LiteFS for distributed SQLite. Worth noting that the old permanent free tier (the one with three shared VMs you may remember) was retired in 2024. New accounts now get a $5 trial credit and a short window (7 days or two VM hours, whichever runs out first) before pay-as-you-go billing kicks in. Fly.io is flexible enough to host almost anything, from Node.js APIs to Python ML services to Go web servers.

The tradeoff is that you're managing Docker containers. You need a Dockerfile, you need to think about image size, and deployments take a minute or two for the build step.

Deno Deploy Overview

Deno Deploy is a serverless edge platform that runs JavaScript and TypeScript on V8 isolates across 35+ global regions. There's no container to build, no Dockerfile to write, and no cold start to worry about. Push to GitHub, and your code is live worldwide in seconds.

The platform is tightly integrated with the Deno runtime. Frameworks like Fresh and Hono deploy seamlessly. You get Deno KV (a globally distributed key-value store) and Deno Queues for async processing baked into the platform. One thing to flag up front, because it bites people who read older comparisons: Deno reworked the platform. The original (now called Deno Deploy Classic, on dash.deno.com) had a free tier of 100,000 requests per day with a 50ms CPU cap per request, and it is being shut down on July 20, 2026. The current Deno Deploy (on console.deno.com) moves to a monthly model. The free tier now grants 1 million requests per month, 100GB of egress, and 15 hours of CPU time, which covers most hobby projects and early-stage products with far less per-request throttling.

Deno Deploy is purpose-built for lightweight, fast, globally distributed applications. It's not trying to be everything. It's trying to be the fastest way to deploy TypeScript to the edge.

Key Differences

Runtime model. Fly.io runs full VMs. Your app has its own operating system, file system, and can install any dependency. Deno Deploy runs V8 isolates, which are lighter but restricted. No file system writes, no native binaries, no arbitrary system calls. If your app needs to shell out to FFmpeg or run Python scripts, Fly.io is your only option. If your app is pure TypeScript, Deno Deploy is simpler and faster.

Language support. Fly.io supports anything that runs in Docker. Python, Go, Rust, Ruby, Java, Node, Deno. Deno Deploy only runs JavaScript and TypeScript through the Deno runtime. This is the biggest filter. If you're not building in JS/TS, the decision is already made.

Deployment speed. Deno Deploy wins decisively. No Docker build, no image push, no VM provisioning. Code goes from git push to globally distributed in seconds. Fly.io deployments take 1-3 minutes depending on your image size and build complexity.

Cold starts. Deno Deploy has near-zero cold starts because V8 isolates spin up in milliseconds. Fly.io VMs stay running (no cold start on the free tier), but if you scale to zero and back, startup takes longer. For APIs where response time matters on every request, Deno Deploy's isolate model is faster.

Data layer. Fly.io gives you managed Postgres, persistent volumes, and the ability to run any database in a container. Deno Deploy offers KV (key-value storage) and nothing else natively. If you need SQL, you pair Deno Deploy with an external database like Neon, PlanetScale, or Supabase. This adds another service to manage and another bill to pay.

Pricing structure. Deno Deploy bills against monthly request, CPU-time, and egress allowances. An idle app costs nothing because there is no machine to keep running. Fly.io charges per Machine by the second, so an always-on app costs money even when idle. The floor is real but small: a single shared-cpu-1x Machine with 256MB of RAM runs about $2.02 per month in the Amsterdam region. For sporadic-traffic projects, Deno Deploy's model is cheaper. For steady-traffic apps that never sleep, Fly.io's per-second VM billing is more predictable and can come out ahead once you exceed the free request allowance.

Ecosystem maturity. Fly.io has been around longer, has more community content, and supports a wider range of use cases. Deno Deploy is newer and more focused. The Deno ecosystem is growing but still smaller than Node's. If you need a specific npm package that doesn't work in Deno, that's a potential blocker.

By the Numbers (2026)

The marketing pages move faster than the blog posts, so here are the figures that actually matter, each checked on 2026-05-28.

Fly.io. No fixed plans. Billing is pay-as-you-go, per second, on the resources a Machine consumes. There is no permanent free tier anymore. New accounts get a $5 trial credit and a window of 7 days or 2 total VM hours (whichever ends first), capped at 10 machines, 20GB of volume storage, up to 2 vCPUs and 4GB of memory per machine. After that you add a card and pay. The cheapest always-on Machine, a shared-cpu-1x with 256MB RAM, is about $2.02 per month in Amsterdam. Stepping up, shared-cpu-2x with 1GB is about $6.64 per month and performance-1x with 2GB is about $32.19 per month, both Amsterdam. Extra RAM is roughly $5 per GB per 30 days. Outbound bandwidth is $0.02 per GB across North America and Europe, rising to $0.04 in Asia Pacific and South America. Inbound transfer is free.

Deno Deploy. The free tier is 1 million requests per month, 100GB of egress, and 15 hours of CPU time, with up to 50 custom domains per organization. The Pro plan is $20 per month for 5 million requests, 200GB of egress, and 40 hours of CPU time, with overages at $2 per additional million requests, $0.50 per additional GB of egress, and $0.05 per additional CPU hour. Heads up that this is the new console.deno.com platform. The legacy Deno Deploy Classic (dash.deno.com), the one with the 100,000 requests per day and 50ms-per-request CPU limit, shuts down on July 20, 2026.

The runtime underneath Deno Deploy. Deno is open source under the MIT license. As of 2026-05-28 the repository sits at 106,891 GitHub stars, and the latest runtime release is v2.8.1, published on 2026-05-27. The deno npm shim pulls roughly 55,993 downloads per week (most installs come through Deno's own installer rather than npm, so treat that figure as a floor, not the whole picture). The first-party framework story is healthy too: Fresh reached 2.3 in April 2026 with zero-JS-by-default islands and View Transitions. Fly.io itself is a closed-source commercial platform, so there are no public repository stars to compare it against.

Real Cost at Solo-Dev Scale

Numbers in isolation do not decide anything, so let me run a realistic solo-dev workload through both pricing models. Assume a TypeScript API plus a small server-rendered site that together handle 2 million requests per month, push around 60GB of egress, and consume roughly 8 hours of total CPU time over the month. That is a real early-stage product, not a toy.

On Deno Deploy. The 60GB of egress and 8 hours of CPU time would both sit inside the free tier, but the request volume gives it away. 2 million requests is double the 1-million free cap, so you move up to Pro at $20 per month. Pro covers 5 million requests, 200GB egress, and 40 CPU hours, and the workload fits comfortably under all three with room to grow. Total: $20 per month, flat, with no idle charge between traffic spikes.

On Fly.io. This workload is steady rather than bursty, so you want at least one always-on Machine. A single shared-cpu-1x with 512MB of RAM is a sane floor for an API plus a small site. The base shared-cpu-1x 256MB Machine is about $2.02 per month in Amsterdam, and the extra 256MB of RAM adds roughly $1.25 per month at the $5-per-GB-per-month rate, so call it about $3.27 per month for compute. The 60GB of egress at $0.02 per GB in Europe adds $1.20. That lands around $4.50 per month for a single Machine. If your traffic justifies a second Machine for redundancy, double the compute and you are near $7.80 per month, still under Deno Deploy Pro.

Reading the result. At this scale Fly.io is the cheaper raw bill because you are paying for one small always-on box rather than crossing a request threshold into a $20 plan. The catch is what each dollar buys. Fly.io hands you a full VM, persistent storage, and the option to colocate a Postgres database, but you own the Dockerfile, the build step, and the scaling decisions. Deno Deploy's $20 buys away all of that operational surface: no containers, no scaling config, near-instant global deploys. The honest read is that the price gap is small enough at solo scale that it should not be the deciding factor. Decide on runtime model and operational taste first, then let the bill confirm it.

When to Choose Fly.io

• Your app uses Python, Go, Rust, or any non-JS/TS language
• You need persistent file storage or full system access
• A managed relational database should be part of the platform
• You want full VM control over your runtime environment
• Your application has system-level dependencies

When to Choose Deno Deploy

• You're building TypeScript-first APIs or web applications
• The fastest possible deployment cycle matters
• Near-zero cold starts are important for your use case
• KV storage covers your data needs, or you're fine with an external database
• The free tier's 1 million monthly requests fits your traffic

The Verdict

These platforms serve overlapping but distinct audiences. Fly.io is the general-purpose edge platform that runs anything. Deno Deploy is the specialized TypeScript edge platform that runs lighter and faster.

If you're a TypeScript developer building APIs, server-rendered sites with Fresh, or lightweight web applications, Deno Deploy is the faster and cheaper option. The deployment speed alone is worth it. Push code, it's live everywhere in seconds. No Docker, no builds, no waiting.

If you need the flexibility to run any language, need persistent storage, or need a relational database on the same platform, Fly.io is the right choice. The VM model is heavier but gives you freedom that V8 isolates can't match.

My recommendation for TypeScript developers is to try Deno Deploy first. The free tier is generous, deployments are instant, and KV handles many data needs. If you hit a wall where you need more runtime flexibility, Fly.io is the natural next step. For everyone else, Fly.io is the default because Deno Deploy simply doesn't support your stack.

Sources

All figures checked on 2026-05-28.

• Fly.io Resource Pricing (official docs)
• Fly.io Free Trial (official docs)
• Fly.io Pricing page
• Deno Deploy Pricing (official)
• Deno Deploy Pricing and Limits (official docs)
• Deno runtime repository (GitHub API)
• Deno v2.8.0 release notes (GitHub)
• Deno runtime stability and releases (official docs)
• Deno deno package weekly downloads (npm API)
• Fresh framework (official)