MongoDB Atlas vs Fly.io
Managed MongoDB with search, vector, stream processing
vs. Run your app close to users, globally
Pricing tiers
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
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 m0 on MongoDB Atlas vs pay-as-you-go on Fly.io.
| Metric | MongoDB Atlas | Fly.io |
|---|---|---|
| backups | 0 backups | — |
| ops per sec | 100 ops/sec | — |
| sort memory mb | 32 MB | — |
| storage gb | 0.5 GB | — |
Features
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.
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 | MongoDB Atlas | Fly.io |
|---|---|---|
| CLI | Atlas CLI, MongoDB Shell (mongosh) | flyctl CLI |
| SDK | Atlas Device SDK (Realm), MongoDB Go Driver, MongoDB Java Driver, MongoDB .NET/C# Driver, mongodb (Node driver), mongodb (Rust), pymongo | — |
| REST | Atlas Admin API, Atlas Data API | Machines API |
| GRAPHQL | — | Fly GraphQL API |
| MCP | MongoDB MCP Server | — |
| OTHER | MongoDB Compass (GUI), MongoDB Wire Protocol | Fly Postgres (wire) |
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