Fly.io vs MongoDB Atlas
Run your app close to users, globally
vs. Managed MongoDB with search, vector, stream processing
Pricing tiers
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
MongoDB Atlas
M0 — Free
Shared cluster, 512 MB storage, 100 ops/sec, 32 MB sort memory. Learning/exploration.
Free
Flex — Serverless
Autoscales 0-500 ops/sec. 5 GB storage. Pay-as-you-go, up to ~$30/mo.
$8/mo
M2 — Shared
Shared, 2 GB storage. Staging / small apps.
$9/mo
M5 — Shared
Shared, 5 GB storage.
$25/mo
M10 — Dedicated
2 GB RAM, 2 vCPU, 10-128 GB storage. First dedicated tier.
$57/mo
M20 — Dedicated
4 GB RAM, 2 vCPU, 20-256 GB storage.
$144/mo
M30 — Dedicated
8 GB RAM, 2 vCPU, 40-512 GB storage.
$389/mo
M40 — Dedicated
16 GB RAM, 4 vCPU, 80 GB-1 TB storage.
$749/mo
M50 — Dedicated
32 GB RAM, 8 vCPU, 160 GB-4 TB storage.
$1440/mo
M60 — Dedicated
64 GB RAM, 16 vCPU.
$2844/mo
M80 — Dedicated
128 GB RAM, 32 vCPU, 750 GB-4 TB.
$5256/mo
M300 — Dedicated
384 GB RAM, 96 vCPU.
$15732/mo
Enterprise
Multi-region Advanced, private network, BYOK, dedicated support.
Custom
Free-tier quotas head-to-head
Comparing pay-as-you-go on Fly.io vs m0 on MongoDB Atlas.
| Metric | Fly.io | MongoDB Atlas |
|---|---|---|
| backups | — | 0 backups |
| ops per sec | — | 100 ops/sec |
| sort memory mb | — | 32 MB |
| storage gb | — | 0.5 GB |
Features
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.
MongoDB Atlas · 14 features
- Atlas App Services — Backend-as-a-service: Functions, HTTPS endpoints, users + auth, sync.
- Atlas Charts — Embedded dashboards + visualizations from Atlas data.
- Atlas Database — Core MongoDB with automated backups, monitoring, scaling on AWS/Azure/GCP.
- Atlas Data Federation — Query across Atlas, S3, and HTTP endpoints in one pipeline.
- Atlas Device Sync (Realm) — Offline-first mobile DB that syncs bidirectionally with Atlas.
- Atlas Search — Apache Lucene-based full-text search integrated into MongoDB aggregation pipelin…
- Atlas Stream Processing — Continuous processing of MongoDB change streams + Kafka. Pipeline aggregations o…
- Atlas Triggers — Database change triggers, scheduled triggers. Run Atlas Functions (Node.js).
- Atlas Vector Search — Vector similarity search via $vectorSearch operator. HNSW index. Up to 4096 dims…
- BYOK Encryption — Bring your own KMS key (AWS KMS, Azure Key Vault, GCP KMS).
- Data API — Read/write via REST. Alternative to drivers for edge/serverless.
- Multi-Region Clusters — Single cluster distributed across multiple regions for HA + low latency.
- Online Archive — Tiered storage: automatic cold data movement to cheaper S3-backed storage.
- Private Networking — VPC Peering, PrivateLink, CIDR allowlist.
Developer interfaces
| Kind | Fly.io | MongoDB Atlas |
|---|---|---|
| CLI | flyctl CLI | Atlas CLI, MongoDB Shell (mongosh) |
| SDK | — | Atlas Device SDK (Realm), MongoDB Go Driver, MongoDB Java Driver, MongoDB .NET/C# Driver, mongodb (Node driver), mongodb (Rust), pymongo |
| REST | Machines API | Atlas Admin API, Atlas Data API |
| GRAPHQL | Fly GraphQL API | — |
| MCP | — | MongoDB MCP Server |
| OTHER | Fly Postgres (wire) | MongoDB Compass (GUI), MongoDB Wire Protocol |
Staxly is an independent catalog of developer platforms. Outbound links to Fly.io and MongoDB Atlas are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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