Sources

Fly.io sources are first-party docs, blog posts and product pages; competitor sources are each vendor’s own public pages. All were checked 2026-11-04 (America/New_York). Each Fly.io docs page also has a Markdown version, and that is what this guide read. The guide is unofficial and is not affiliated with Fly.io.

This page is drawn from https://docs.fly.io/llms.txt, https://fly.io/blog/, https://fly.io/docs/sprites/, https://fly.io/sprites and the competitor pages listed below.

How this guide was sourced

• Docs. The index is https://docs.fly.io/llms.txt, and every page it lists was read in its .md form. 874 pages were downloaded on 2026-11-04. A docs page such as docs/about/pricing.md is cited as https://fly.io/docs/about/pricing/.
• Blog. All 201 posts at https://fly.io/blog/ (from 2020-01-22 to 2026-10-23) were read through a local copy of the corpus. Blog facts are cited to the post and carry the post date, because many posts describe the platform as it was then. Where a post and a current docs page differ, the guide treats the docs as current and the post as history, and says so.
• Sprites. The Sprites docs under https://fly.io/docs/sprites/ and the product page https://fly.io/sprites were read. The Sprites site https://sprites.dev/ was also fetched, which is where a trial-credit conflict with the platform docs turned up (see below).
• Live first-party pages. The status page (https://status.flyio.net/), the support page (https://fly.io/support), the legal sub-processor list (https://fly.io/legal/sub-processors/) and the community forum (https://community.fly.io/) were fetched directly on 2026-11-04.
• Competitors. Every competitor fact comes from that vendor’s own public page, fetched 2026-11-04, and is linked in the sentence that uses it. Where a pricing page is rendered by script and the number could not be read, the guide leaves the number out and marks it [verify]. No competitor price comes from memory.
• Derived figures. Numbers labeled derived are arithmetic on prices quoted on the page, with the inputs shown beside them.
• [verify] badges. These mark statements the sources do not settle, or settle in two different ways. They are collected at the end of this page.

Fly.io: Key pages

These are the most-cited Fly.io pages in the guide. Counts are not shown; the order is by topic.

Platform and pricing

• Fly.io docs index: https://docs.fly.io/llms.txt (fetched; it lists every docs page).
• Resource pricing: https://fly.io/docs/about/pricing/ (Machine, volume, snapshot, IP and bandwidth prices; the most-cited page in the guide.)
• Pricing calculator: https://fly.io/calculator/ (Interactive cost estimate.)
• Free trial: https://fly.io/docs/about/free-trial/ (What a new organization gets and the limits on it.)
• Billing: https://fly.io/docs/about/billing/ (How and when usage is billed.)
• Cost management: https://fly.io/docs/about/cost-management/ (What controls exist for spend.)
• Regions: https://fly.io/docs/reference/regions/ (Where Fly.io runs.)
• Healthcare and compliance: https://fly.io/docs/about/healthcare/ (HIPAA-related guidance and the compliance package.)
• Security overview: https://fly.io/docs/security/security-at-fly-io/ (How Fly.io describes its security posture.)
• Shared responsibility: https://fly.io/docs/security/shared-responsibility/ (What Fly.io covers and what the customer covers.)

Apps, Machines, volumes

• Getting started essentials: https://fly.io/docs/getting-started/essentials/ (The core objects and workflow.)
• Launch demo: https://fly.io/docs/getting-started/launch-demo/ (First deploy walkthrough.)
• Apps overview: https://fly.io/docs/apps/overview/ (What an app is on Fly.io.)
• Machines overview: https://fly.io/docs/machines/overview/ (Machines as Firecracker microVMs, and their lifecycle.)
• Machine states: https://fly.io/docs/machines/machine-states/ (The states a Machine moves through.)
• Machine placement: https://fly.io/docs/machines/guides-examples/machine-placement/ (How Machines are placed on hosts.)
• Autostop and autostart: https://fly.io/docs/launch/autostop-autostart/ (Scale-to-zero behavior and settings.)
• Suspend and resume: https://fly.io/docs/reference/suspend-resume/ (Snapshot-based suspend.)
• Volumes overview: https://fly.io/docs/volumes/overview/ (Persistent storage, one volume to one Machine.)
• Volume snapshots: https://fly.io/docs/volumes/snapshots/ (Backups and retention.)
• Configuration reference (fly.toml): https://fly.io/docs/reference/configuration/ (Every fly.toml setting.)
• Deploy: https://fly.io/docs/launch/deploy/ (Deploy strategies and flow.)
• Resilient apps with multiple Machines: https://fly.io/docs/blueprints/resilient-apps-multiple-machines/ (Why one Machine is not highly available.)
• Host unavailable: https://fly.io/docs/apps/trouble-host-unavailable/ (What happens when a host fails.)

Network and edge

• Fly Proxy: https://fly.io/docs/reference/fly-proxy/ (Routing, TLS termination and load balancing.)
• Load balancing: https://fly.io/docs/reference/load-balancing/ (How requests are spread across Machines.)
• Autostop/autostart in the proxy: https://fly.io/docs/reference/fly-proxy-autostop-autostart/ (How the proxy wakes a stopped Machine.)
• Services: https://fly.io/docs/networking/services/ (Ports, handlers and concurrency settings.)
• Private networking: https://fly.io/docs/networking/private-networking/ (6PN, WireGuard and .internal DNS.)
• Flycast: https://fly.io/docs/networking/flycast/ (Private load-balanced addresses.)
• Dynamic request routing: https://fly.io/docs/networking/dynamic-request-routing/ (fly-replay and region steering.)
• Custom domains: https://fly.io/docs/networking/custom-domain/ (Domains and certificates.)
• Architecture reference: https://fly.io/docs/reference/architecture/ (Hosts, Firecracker, the control plane.)

Data and automation

• Postgres: https://fly.io/docs/postgres/ (Postgres options and limits.)
• Machines API: https://fly.io/docs/machines/api/working-with-machines-api/ (REST access to Machines.)
• flyctl integration: https://docs.fly.io/flyctl/integrating/ (Using flyctl in scripts and CI.)
• Secrets: https://docs.fly.io/apps/secrets/ (Setting and using secrets.)
• Tokens: https://docs.fly.io/security/tokens/ (Token types and scopes.)
• Org roles and permissions: https://fly.io/docs/security/org-roles-permissions/ (Admin and Member roles.)
• SSO: https://fly.io/docs/security/sso/ (Sign-in options for organizations.)
• Infrastructure without Terraform: https://docs.fly.io/blueprints/infra-automation-without-terraform/ (The blueprint on automation.)
• AWS to Fly guide: https://fly.io/docs/reference/aws-to-fly-guide/ (Mapping AWS concepts to Fly.io.)
• Migrate from Heroku: https://fly.io/docs/getting-started/migrate-from-heroku/ (Moving a Heroku app.)

Sprites

• Sprites docs: https://fly.io/docs/sprites/ (Sprites documentation root.)
• Sprites product page: https://fly.io/sprites (Positioning, plans and trial credit.)
• Sprites site: https://sprites.dev/ (Separate marketing site; the $30 trial claim is here.)
• Lifecycle: https://fly.io/docs/sprites/concepts/lifecycle/ (States, resources and what persists.)
• Checkpoints: https://fly.io/docs/sprites/concepts/checkpoints/ (Save and restore of a Sprite’s files.)
• Networking: https://fly.io/docs/sprites/concepts/networking/ (Sprite URLs and egress.)
• Working with Sprites: https://fly.io/docs/sprites/working-with-sprites/ (Day-to-day usage guide.)

Support and reliability

• Support docs: https://fly.io/docs/about/support/ (Plans and what is in scope.)
• Support page: https://fly.io/support (Plan prices and the Enterprise SLA line.)
• Status page: https://status.flyio.net/ (Live platform health.)
• Status history: https://status.flyio.net/history (Past incidents.)
• Infra log: https://fly.io/infra-log (Fly.io’s own incident write-ups.)
• Compliance: https://fly.io/compliance (Certifications overview.)

Blog posts used most

• Design and implementation of Sprites: https://fly.io/blog/design-and-implementation/ (January 2026 design post.)
• Kurt, Scott, money, Sprites: https://fly.io/blog/kurt-scott-money-sprites/ (2026-07-24 company direction.)
• Corrosion: https://fly.io/blog/corrosion/ (The service-discovery database.)
• Carving the scheduler out of our orchestrator: https://fly.io/blog/carving-the-scheduler-out-of-our-orchestrator/ (Scheduling design.)
• We were wrong about GPUs: https://fly.io/blog/wrong-about-gpu/ (2025-02-14 GPU direction.)
• Sprites Block Device: https://fly.io/blog/sprites-block-device/ (2026 Sprites storage change.)
• Sprites MCP: https://fly.io/blog/sprites-mcp/ (MCP server and default token limits.)
• Docker without Docker: https://fly.io/blog/docker-without-docker/ (2021 image-to-microVM pipeline.)

Competitor sources

Pages read for /competitive/, /pitch/ and /objections/. Each vendor page was fetched 2026-11-04.

Platform-as-a-service vendors

• Render. https://render.com/pricing (Hobby workspace price, Free instance size, Sandboxes in beta.) https://docs.render.com/free (Free web services spin down after 15 minutes idle and lose local files.)
• Railway. https://railway.com/pricing (Hobby and Pro minimum usage, per-second CPU and memory rates, Sandbox rates.)
• Heroku. https://www.heroku.com/pricing and https://www.heroku.com/pricing/ (Dyno prices from Eco to Performance-M and the idle sleep behavior.) https://devcenter.heroku.com/articles/dyno-types (Eco dyno subscription and hours pool.)
• Vercel. https://vercel.com/pricing (Hobby, Pro and Enterprise SLA line, Active CPU and memory rates.)
• DigitalOcean App Platform. https://docs.digitalocean.com/products/app-platform/details/pricing/ (Container sizes with fixed monthly prices and per-second billing.) https://www.digitalocean.com/pricing/app-platform (Free tier for static sites.)

Cloud providers

• Cloudflare. https://developers.cloudflare.com/workers/platform/pricing/ (Workers plans and included requests.) https://developers.cloudflare.com/containers/pricing/ (Container sizes and per-second rates.) https://developers.cloudflare.com/durable-objects/platform/pricing/ (Request and duration charges that apply alongside Containers.) https://developers.cloudflare.com/sandbox/ (Sandbox isolation description and plan requirement.)
• AWS. https://aws.amazon.com/apprunner/pricing/ (Provisioned and active rates in the regions named.) https://aws.amazon.com/fargate/pricing/ and https://aws.amazon.com/lambda/pricing/ (Pricing shapes only; rates could not be read.) https://aws.amazon.com/lightsail/pricing/ (Fixed bundles.)
• Google Cloud Run. https://cloud.google.com/run/pricing (Billing granularity and free tier.) https://cloud.google.com/run/docs/about-instance-autoscaling (Scale to zero and instance limits.)

Agent-sandbox vendors

• E2B. https://e2b.dev/pricing (Per-second CPU and memory rates, plan tiers.) https://e2b.dev/docs (Pause behavior and session limits.)
• Modal. https://modal.com/pricing (Sandbox CPU and memory rates, GPU list.) https://modal.com/docs/guide/sandbox (Runtime options and default lifetime.)
• Daytona. https://www.daytona.io/pricing (Per-hour CPU and memory rates.) https://www.daytona.io/docs/en/sandboxes.md (Default sandbox size and the GPU, Windows and macOS options.)
• Vercel Sandbox. https://vercel.com/docs/vercel-sandbox (Isolation description and session limits.) https://vercel.com/docs/vercel-sandbox/pricing and https://vercel.com/docs/sandbox/pricing (Active CPU and memory rates, quotas.)

Known source conflicts and gaps

These [verify] items recur across pages. Each is quoted or paraphrased from the page that raises it; none is settled by the sources.

• Trial credit. The platform trial page says $1 for 7 days; the Sprites site advertises “$30 in trial credits”. Raised in /economics/, /poc/, /learn/agents/, /objections/, /pitch/ and /whiteboard/agent-sandbox/. Check the dashboard of the account you demo with before promising either (https://fly.io/docs/about/free-trial/, https://fly.io/sprites).
• GPU availability. The 2025-02-14 post says a “v2” should not be expected, and https://fly.io/docs/gpus/ and https://fly.io/gpu redirect to that post as fetched. Whether new customers can still provision GPU Machines is unsettled. Raised in /objections/, /learn/what-is-fly/, /learn/machines-and-apps/ and /economics/ (https://fly.io/blog/wrong-about-gpu/).
• Fundraise size. The July 2026 post says Fly.io raised more money, but the amount is not in the text. Raised in /objections/ and /learn/what-is-fly/ (https://fly.io/blog/kurt-scott-money-sprites/).
• SLA terms. Only the Enterprise support plan lists a “99.9% uptime SLA”; no public page gives credit tiers, measurement rules or exclusions. Raised in /faq/ and /learn/teams-enterprise/ (https://fly.io/support/).
• Sprites storage and OS. The product page calls the S3 block device “early access” while the blog says it will be the filesystem going forward; the maintenance guide says Ubuntu 26.04 while the working guide says Ubuntu 25.10. Raised in /learn/agents/ (https://fly.io/blog/sprites-block-device/, https://fly.io/docs/sprites/sprite-maintenance/).
• Old posts versus current docs. Several blog facts are years old (build pipeline, volume snapshot retention, kill_timeout, SOC2 status, partner free tiers) and are flagged to confirm against current docs. Raised in /learn/architecture/, /blog/ and its continuation pages (https://fly.io/blog/docker-without-docker/, https://fly.io/blog/volumes-expand-restore/).
• Competitor rates rendered by script. The AWS Fargate and Lambda pages and the Cloud Run unit rates could not be read, so no number is quoted. Raised in /competitive/ (https://aws.amazon.com/fargate/pricing/, https://aws.amazon.com/lambda/pricing/, https://cloud.google.com/run/pricing).
• Fly.io price table. The preset-by-region table on the pricing page is rendered by JavaScript and was not readable beyond a few presets and the iad and ewr regions. Raised in /economics/ (https://fly.io/docs/about/pricing/).
• Support internals. How a ticket reaches engineering, and whether Litestream is in scope for support, are not documented publicly. Raised in /support/ and /learn/integrations/ (https://docs.fly.io/about/support/).
• Reliability trend. Only the window shown on the status history page was read, so claims about a year-long trend are not supported. Raised in /reliability/ (https://status.flyio.net/history).

Branding

The nixfred hexagon logo is copied unchanged from the nixfredOS repo brand/ folder.