Hosting Options¶

Choosing the right hosting plan is the highest-impact early decision for an Azure Functions workload.

This page compares the four plans covered in this guide: Consumption (Y1), Flex Consumption (FC1), Premium (EP), and Dedicated (App Service Plan).

All comparisons are based on Microsoft Learn documentation.

flowchart TD
    A[Start] --> B{New serverless app?}
    B -->|Yes| C[Flex Consumption]
    B -->|No| D{Need warm capacity controls?}
    D -->|Yes| E[Premium]
    D -->|No| F{Already on App Service capacity?}
    F -->|Yes| G[Dedicated]
    F -->|No| H[Consumption\nlegacy only]

Quick guidance¶

• Start with Flex Consumption for most new serverless apps.
• Use Premium when you need stronger cold-start control and advanced enterprise patterns.
• Use Dedicated when you already operate App Service capacity or need fixed, predictable capacity behavior.
• Use Consumption (Y1) only when legacy constraints require it (especially Windows-only dependencies).

Reference:

• Azure Functions scale and hosting options

Decision matrix¶

Detailed plan notes¶

Consumption (Y1)¶

Use when you have a legacy dependency that still requires this plan, especially Windows-specific scenarios.

Important Microsoft Learn notes:

• Classified as a legacy hosting option
• New serverless apps should generally use Flex Consumption
• Linux Consumption has retirement milestones and reduced future language/version evolution

Reference:

• Consumption plan (legacy)

Flex Consumption (FC1)¶

Use for most new serverless workloads.

Strengths:

• Event-driven serverless economics
• VNet integration support
• Configurable instance memory sizes
• Per-function scaling behavior and concurrency tuning
• Optional always-ready instances for lower startup latency

Reference:

• Flex Consumption plan

Premium (EP)¶

Use when you need serverless elasticity with stronger warm-capacity control and broader enterprise knobs.

Strengths:

• Always-ready and prewarmed instances
• VNet integration
• Longer execution support with unbounded timeout configuration path
• Multiple apps per plan and richer App Service integration model

Reference:

• Premium plan

Dedicated (App Service Plan)¶

Use when you already run App Service capacity and want to colocate functions with predictable resource allocation.

Strengths:

• Fixed capacity model with standard App Service economics
• Works well for always-on style workloads
• Useful when consolidation with existing web apps is intentional

Reference:

• Dedicated plan

Decision flow¶

Use this sequence to pick a plan with minimal rework:

1. Need new serverless app? Start with FC1.
2. Need strict warm capacity behavior or multi-app premium hosting? Evaluate EP.
3. Already paying for underutilized App Service capacity? Evaluate Dedicated.
4. Blocked by legacy Windows-only requirements? Use Y1 with migration plan toward FC1 where feasible.

Operational implications to confirm early¶

Before finalizing a plan, confirm:

• Expected idle/burst traffic pattern
• Required private networking model
• HTTP latency expectations during scale events
• Long-running execution requirements and timeout policy
• Deployment strategy (including rollback behavior)

CLI examples (long flags only)¶

Use these examples as pattern references only. Validate exact command combinations with current Microsoft Learn CLI pages before production use.

az functionapp create \
    --resource-group "$RG" \
    --name "$APP_NAME" \
    --storage-account "$STORAGE_NAME" \
    --consumption-plan-location "$LOCATION" \
    --runtime python \
    --functions-version 4

az functionapp plan create \
    --resource-group "$RG" \
    --name "$PLAN_NAME" \
    --location "$LOCATION" \
    --sku EP1 \
    --is-linux

If sharing output snippets in runbooks, mask identifiers:

{
    "id": "/subscriptions/<subscription-id>/resourceGroups/rg-example/providers/Microsoft.Web/sites/func-example",
    "principalId": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "tenantId": "<tenant-id>"
}

Cost guidance¶

Do not hardcode plan pricing into internal docs because regional and meter-specific pricing changes.

Use official pricing tools:

• Azure Functions pricing
• Azure pricing calculator

See Also¶

• Overview
• Learning Paths
• Repository Map
• Platform Hosting
• Deployment Scenarios — Cross-plan comparison of VNet, PE, identity, and deployment patterns

Sources¶

• Azure Functions scale and hosting options
• Consumption plan (legacy)
• Flex Consumption plan
• Premium plan
• Dedicated plan