Datadog vs Fly.io
Enterprise cloud monitoring — infra, APM, logs, RUM, security, LLM
vs. Run your app close to users, globally
Pricing tiers
Datadog
Serverless Monitoring
$0.13 per month per 1M invocations.
$0 base (usage-based)
Free
Up to 5 hosts, 1-day metric retention. Community edition of Agent.
Free
Logs Ingestion
$0.10 per ingested/scanned GB per month.
$0 base (usage-based)
Logs Standard Index
$1.70 per million log events/month.
$0 base (usage-based)
Logs Flex Storage
$0.05 per million events stored/month.
$0 base (usage-based)
Infra Pro
Per host per month (annual billing). 15-month metric retention, 500+ integrations.
$15/mo
Infra Enterprise
Per host. Advanced features, Network Flow Monitoring.
$23/mo
APM
Per host (with Infra attached). Distributed tracing.
$31/mo
APM Pro
Per host. Continuous Profiler + Data Streams Monitoring.
$35/mo
APM Enterprise
Per host. App & API Protection + more.
$40/mo
Enterprise
Volume discounts, dedicated CSM, regional data residency.
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 Datadog vs pay-as-you-go on Fly.io.
| Metric | Datadog | Fly.io |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
Datadog · 19 features
- APM — Distributed tracing + service catalog + code hotspots.
- Application Security — Runtime attack detection, threat intelligence, IAST.
- CI Visibility — Test + pipeline performance analytics.
- Cloud SIEM — Security events correlation, detection rules, audit trails.
- Continuous Profiler — Always-on CPU, memory, lock profiling in production.
- Dashboards — Pre-built + custom dashboards.
- Database Monitoring — Slow query detection for Postgres, MySQL, Mongo, Oracle, SQL Server.
- Incident Management — Built-in incident response with postmortems.
- Infrastructure Monitoring — Host, container, k8s metrics. 700+ integrations. Live process + container maps.
- LLM Observability — OpenAI, Anthropic, etc. trace + cost + prompt eval.
- Log Management — Ingest any logs, structured or raw. Pipelines, parsing, archives to S3.
- Monitors — Anomaly, forecast, outlier, composite monitors.
- Network Performance Monitoring — Packet-level analysis, flow monitoring.
- Notebooks — Runbook-style dashboards with queries + docs.
- Real User Monitoring — Frontend performance, JS errors, user sessions, Core Web Vitals.
- Serverless Monitoring — AWS Lambda, Google Cloud Functions, Azure Functions observability.
- Service Catalog — Service inventory with ownership + documentation.
- Synthetics — Synthetic HTTP + browser tests, API tests, mobile tests.
- Workflow Automation — No-code workflows triggered by events.
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 | Datadog | Fly.io |
|---|---|---|
| CLI | Datadog Agent | flyctl CLI |
| SDK | dd-trace-dotnet, dd-trace-go, dd-trace-java, dd-trace-js (RUM), dd-trace (Node), ddtrace (Python), ddtrace (Ruby) | — |
| REST | Datadog REST API | Machines API |
| GRAPHQL | — | Fly GraphQL API |
| MCP | Datadog MCP | — |
| OTHER | OpenTelemetry (OTLP), Webhooks | Fly Postgres (wire) |
Staxly is an independent catalog of developer platforms. Outbound links to Datadog and Fly.io are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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