Inngest vs Fly.io
Durable functions + event-driven workflows for modern apps
vs. Run your app close to users, globally
Pricing tiers
Inngest
Free
$0. 50K steps/mo + 1K concurrent executions. 7-day log retention. 1 environment.
Free
OSS (self-host)
Free forever. Inngest Dev Server + self-hosted Inngest runtime. Apache 2.0.
$0 base (usage-based)
Starter
$20/mo. 250K steps/mo. 5K concurrency. 14-day retention. 3 envs.
$20/mo
Pro
$75/mo. 1M steps/mo. 10K concurrency. 30-day retention. Priority support.
$75/mo
Enterprise
Custom. SSO, HIPAA, dedicated clusters, self-host with Inngest Enterprise.
Custom
Fly.io
Pay-as-you-go
No monthly fee. Machines billed per second. Free allocations: ~3 small shared machines + 3 GB volumes.
$0 base (usage-based)
Shared CPU 1x — 256 MB
Entry VM. 1 shared vCPU, 256 MB RAM. ~$2.02/month continuously on.
$2/mo
Performance 1x — 2 GB
Dedicated 1 vCPU, 2 GB RAM.
$32/mo
Reservation — Shared (1 yr)
$36/year for $5/mo credit (40% savings).
$36/mo
Shared CPU 8x — 16 GB
8 shared vCPU, 16 GB RAM.
$89/mo
Performance 16x — 128 GB
Dedicated 16 vCPU, 128 GB RAM.
$1014/mo
Enterprise
Custom. Dedicated capacity, SLA.
Custom
Free-tier quotas head-to-head
Comparing free on Inngest vs pay-as-you-go on Fly.io.
| Metric | Inngest | Fly.io |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
Inngest · 14 features
- AgentKit — Build AI agents as durable Inngest functions.
- Auto Retries — Configurable retries with exponential backoff.
- Concurrency Controls — Per-function and per-user concurrency limits.
- Cron Triggers — Scheduled functions via cron syntax.
- Debounce — Coalesce rapid-fire events into one execution.
- Dev Server — Local Inngest runtime for dev.
- Durable Steps — step.run, step.sleep, step.waitForEvent.
- Event System — Typed events with schemas.
- Fan Out / Batching — Process many events in parallel with batch control.
- Priority Lanes — Route premium customers to faster execution.
- Rate Limiting — Throttle events per key.
- Realtime — Stream function output to clients.
- Replay — Re-run past functions with new code.
- Self-Host — OSS runtime — run your own Inngest.
Fly.io · 14 features
- Auto Stop/Start — Machines auto-stop when idle, start on request (like scale-to-zero).
- Certs — Let's Encrypt + wildcard certs managed.
- Fly GPU — A100/L40S/A10 on-demand GPU machines.
- Fly Kubernetes (FKS) — Managed Kubernetes on Fly machines.
- Fly Machines — Firecracker microVMs. Start in <1s. Run any Docker image.
- Fly Postgres — Managed Postgres via Supabase partnership (2024). Also legacy self-run Postgres …
- fly-replay headers — Route request to another region at app level.
- Fly Volumes — Persistent SSD attached to a Machine. Encrypted at rest.
- Global Anycast — Single IP routes to the closest region automatically.
- LiteFS — Distributed SQLite with primary/replica across regions.
- Private Networks — 6PN WireGuard mesh. Connect machines across regions privately.
- Secrets — Encrypted env vars propagated to all regions.
- Tigris (partner) — S3-compatible storage for Fly apps. By partner.
- Upstash Redis (partner) — Managed Redis via Upstash.
Developer interfaces
| Kind | Inngest | Fly.io |
|---|---|---|
| CLI | inngest-cli (dev server) | flyctl CLI |
| SDK | inngestgo, inngest (Python), inngest (TS/Node) | — |
| REST | Inngest REST API | Machines API |
| GRAPHQL | — | Fly GraphQL API |
| MCP | Inngest MCP | — |
| OTHER | Inngest Cloud Dashboard | Fly Postgres (wire) |
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