Azure App Service Limits and Quotas

This document provides information about the limits and quotas that apply to Azure App Service.

Introduction

Azure App Service is a fully managed platform for building, deploying, and scaling web apps, mobile back ends, and APIs. Understanding the limits and quotas is crucial for efficient resource utilization and performance optimization. These limits are designed to ensure fair usage and prevent unintended resource consumption.

General Limits

The following are general limits that apply across Azure App Service. These are often soft limits and can sometimes be increased upon request.

Resource	Limit	Notes
Number of App Service Plans per Subscription	50	Can be increased upon request.
Number of Apps per App Service Plan	Varies by tier (e.g., 10 for Free, 20 for Shared, 100 for Basic/Standard/Premium)	See tier-specific limits below.
Storage per App	50 GB (default)	Can be increased using custom configurations or external storage solutions.
Deployment Slots per App	20	Includes production slot.
Allowed Characters in App Name	Alphanumeric and hyphens (-). Cannot start or end with a hyphen.

App Service Plan Tier-Specific Limits

Different pricing tiers for App Service Plans have varying limits on compute resources, performance, and scalability. Here's a summary:

Tier	Compute Resources (vCPU/Memory)	Instance Count	Max Apps per Plan	Features
Free	Limited	1	10	Shared infrastructure, suitable for development and testing.
Shared	Limited	1	20	Shared infrastructure with slightly more resources than Free.
Basic	Dedicated, tiered options (e.g., B1, B2, B3)	Up to 3	50	Dedicated instances, custom domains, SSL.
Standard	Dedicated, tiered options (e.g., S1, S2, S3)	Up to 10	100	Automated backups, staging environments, VNet integration (limited).
Premium	Dedicated, tiered options (e.g., P1v2, P2v2, P3v2)	Up to 20	100	More compute power, advanced VNet integration, deployment slots.
Isolated	Dedicated, isolated environments	Up to 20	100	Fully isolated network, highest performance and security.
Consumption (Azure Functions)	Event-driven, auto-scaling	N/A (scaled by triggers)	N/A	Pay-per-execution, ideal for event-driven workloads.

For detailed specifications on vCPU, memory, and storage for each tier, refer to the official Azure App Service pricing page.

API Management Limits

While API Management is a separate service, it often works in conjunction with App Service. General Azure limits for API Management include:

Number of APIs per Gateway: 1000
Number of Products per Gateway: 1000
Number of Policies per API: 100

For specific API Management limits, please consult the API Management documentation.

Best Practices to Manage Limits

Choose the Right Tier: Select an App Service Plan tier that matches your application's performance and scaling needs.
Monitor Usage: Regularly monitor your App Service Plan and individual app metrics (CPU, memory, requests) using Azure Monitor.
Scale Strategically: Configure auto-scaling rules based on metrics to handle traffic fluctuations.
Optimize Applications: Ensure your applications are efficient to minimize resource consumption.
Consider Microservices: For complex applications, breaking them down into smaller, independent microservices can improve manageability and scalability.
Utilize Deployment Slots: Use deployment slots for testing new versions without impacting production traffic.

Important Note on Quotas

Quotas are generally fixed limits that are harder to increase. For example, the number of App Service Plans per subscription is a quota. If you anticipate needing more resources than these limits allow, plan accordingly and contact Azure support well in advance.

Troubleshooting and Support

If you encounter issues related to limits or quotas, consider the following:

Check Azure Monitor Metrics: Identify which resource is hitting its limit.
Review Application Logs: Look for errors or performance bottlenecks within your application.
Consult Azure Advisor: It may provide recommendations for optimizing performance and cost.
Contact Azure Support: For quota increases or complex issues, open a support request.

You can find more troubleshooting tips in the Azure App Service diagnostic logs documentation.