Cloud Run vs App Runner: Serverless Container Platforms
| Dimension | Google Cloud Run | AWS App Runner |
|---|---|---|
| Deployment Inputs | Container image (any language/runtime). Optional Cloud Build + Buildpacks. | Container image or source repository (App Runner builds via AWS CodeBuild/Buildpacks). |
| Scaling Model | Scale to zero by default, request-based autoscaling. Min instances for warm starts. | Runs at least one instance; scales based on concurrency and CPU utilisation. |
| Networking | Regional service endpoints, VPC connectors, internal-only services. | Public endpoint by default, VPC access via VPC connectors; custom domains with ACM. |
| Traffic Controls | Weighted traffic splitting, revisions, gradual rollouts. | Automatic blue/green deployments with health checks; manual traffic shifting. |
| Observability | Cloud Logging, Cloud Trace, Error Reporting, Cloud Monitoring integrations. | CloudWatch metrics/logs, X-Ray tracing (with instrumentation). |
| Pricing | Billed per vCPU-second, memory-second, requests; first 2M requests free. Scale-to-zero reduces idle cost. | Billed per vCPU-second and memory-second plus provisioned instances; minimum charged service time even when idle. |
Strengths
Cloud Run
- Runs on Google’s managed Knative; portable to Anthos or self-managed Knative clusters.
- Scale-to-zero and per-request billing suit bursty workloads.
- Built-in identity integration with IAM and service accounts; supports VPC Service Controls.
App Runner
- Tight AWS integration (ECR, Secrets Manager, CloudWatch). Deploy straight from ECR or GitHub.
- Simplified networking and TLS certificate management via ACM.
- Supports container health checks and automatic platform patching without ECS setup.
Considerations
- Cold Starts: Cloud Run can cold start when scaling from zero; set
min-instancesto keep warm. App Runner keeps at least one instance running, trading cost for latency. - Regional Availability: Verify regions (Cloud Run covers most GCP regions; App Runner currently available in a subset of AWS regions).
- Compliance: Both support private networking; Cloud Run integrates with Cloud Armor, while App Runner can sit behind AWS WAF/CloudFront.
Getting Started
Evaluate both by deploying the same container, observing cold-start latency, scaling behaviour, and ops workflows in your monitoring stack.