AWS First Steps
Compute

AWS App Runner

A fully managed service that automatically builds, deploys, and scales web applications and APIs from container images or source code

About 5 min readWritten and edited by Awashiro

Overview

AWS App Runner is a fully managed service that lets you deploy and operate containerized web applications and APIs without any infrastructure knowledge. Simply specify an ECR container image or a GitHub repository with source code, and the build, deployment, TLS termination, load balancing, and auto-scaling are automatically configured. When traffic drops to zero, instances scale down to the minimum count, and they automatically scale out as requests increase.

Selection Criteria vs. ECS Fargate and Lambda

App Runner, ECSFargate, and Lambda can all run containers or code in a serverless fashion, but they differ in the trade-off between abstraction level and control. App Runner has the highest abstraction level - you rarely need to think about VPC configuration, load balancer setup, task definitions, or service discovery. It's well suited for quickly deploying web applications and REST APIs. ECS Fargate offers more control than App Runner, letting you fine-tune container CPU/memory, sidecar containers, volume mounts, and health checks through task definitions. It includes production-ready features like service-to-service communication control (ECS Service Connect), service discovery (Cloud Map), and Blue/Green deployments (CodeDeploy integration). Choose Fargate for microservice architectures or complex networking requirements. Lambda specializes in event-driven function execution and supports triggers beyond HTTP requests (S3 events, SQS messages, schedules). However, it has a 15-minute execution time limit (as of September 2026) and isn't suited for workloads that hold long-lived connections. The typical division of labor has been: App Runner for simple web apps, Fargate for production microservices, and Lambda for event-driven processing. However, AWS has closed App Runner to new customers (as of September 2026; existing customers can continue to use it), so for new builds, ECS Fargate and Lambda are the realistic choices.

Deployment Pipeline and Auto-Scaling Mechanics

App Runner supports two kinds of deployment sources: ECR container images and source code repositories such as GitHub or Bitbucket. With ECR sources, you can configure automatic deployment triggered by image pushes, so deployment completes simply by pushing an image to ECR from your CI/CD pipeline. With GitHub sources, App Runner automatically builds and deploys the source code. It supports managed runtimes for several languages (see the official documentation for the current list), with build and start commands defined in apprunner.yaml. Auto-scaling operates based on concurrent request count - when the maximum concurrent requests per instance (default 100, as of September 2026) is exceeded, it scales out. Setting the minimum instance count to 1 keeps one instance always running even with zero traffic, avoiding cold starts. The minimum cannot be set to 0, so if you need true scale-to-zero, consider Lambda instead. During deployment, rolling updates are performed automatically, with traffic switching to the new version only after it passes health checks.

VPC Connectivity and Private Resource Access

App Runner has a public endpoint by default, but by configuring a VPC connector, you can access private resources within a VPC (RDS, ElastiCache, DocumentDB, etc.). A VPC connector establishes a network connection between the App Runner service and the VPC, reaching private resources through specified subnets and security groups. An important caveat: once a VPC connector is configured, all outbound traffic from App Runner routes through the VPC, so a NAT Gateway is required for internet access. This incurs additional costs, so cost estimation is necessary upfront for applications that call external APIs. For inbound traffic, App Runner's private endpoint feature lets you build internal services accessible only from within the VPC. This is ideal for internal admin dashboards or inter-microservice communication that shouldn't be exposed to the internet. Pricing is based on hourly charges for instance vCPU and memory, and what is billed differs between active request processing and idle periods, so see the official AWS pricing pages for details.

References (Official AWS Resources)

The primary sources for this page are the official AWS website and documentation. Check the official pages below for the latest specifications and pricing.

If this page and the official documentation disagree, treat the official documentation as authoritative.

ShareXB!

Related Terms

Amazon ECSAWS FargateAWS LambdaAmazon ECRAWS Elastic Beanstalk

Related Services

Amazon ECSAWS FargateAmazon ECRAWS Lambda

Related Articles

Container Orchestration with Amazon ECS - Task Definition and Service DesignA comprehensive guide covering task definition design, service deployment strategies, choosing between Fargate and EC2, and Auto Scaling configuration patterns.Simplifying Container Deployment - Zero-Configuration Deployment with AWS App RunnerLearn how to deploy containerized web applications with AWS App Runner. This guide covers the differences from ECS/Fargate, auto scaling, VPC integration, and CI/CD pipeline connectivity.AWS CodeDeploy Deployment Strategies - Blue/Green Deployments for EC2, ECS, and LambdaManage deployment strategies across three platforms - EC2, ECS, and Lambda - in a unified way. This article covers ECS blue/green deployments and automatic rollback triggered by CloudWatch alarms.Amazon ECR Container Image Management - Lifecycle Policies and Image ScanningLearn how to automatically clean up old images with private repository lifecycle policies and detect vulnerabilities with image scanning.Breaking Down ECS on Fargate Cost Structure - Practical Combinations of Spot, ARM, and ScalingBreak down ECS on Fargate pricing across CPU, memory, and storage, and learn practical cost optimization techniques combining Fargate Spot, Graviton (ARM), and Service Auto Scaling.

Similar Terms and Articles

Simplifying Container Deployment - Zero-Configuration Deployment with AWS App RunnerLearn how to deploy containerized web applications with AWS App Runner. This guide covers the differences from ECS/Fargate, auto scaling, VPC integration, and CI/CD pipeline connectivity.AWS App RunnerA fully managed service for deploying and running containerized web applications and APIsServerless Container Operations with AWS Fargate - Usage Patterns for ECS and EKSRun serverless containers without managing instances. Learn how to choose between ECS and EKS, and optimize costs through task sizing.