Quick answer
AWS Lambda - AWS Lambda wins for most builders who want the broadest serverless option and the clearest path from free to pay-as-you-go, while Azure Functions is the better pick if you expect Durable Functions, Flex Consumption, or Azure-native integration to matter more.
How the free tiers compare
Both products give you a real free tier for event-driven compute, but they differ in how far that free tier stretches and how the paid path behaves. AWS Lambda’s free tier is straightforward: 1 million requests and 400,000 GB-seconds per month, with the same core model continuing into paid usage. Azure Functions also gives monthly grants, but it splits the experience across Consumption, Flex Consumption, Premium, and Durable Task Scheduler options, which makes it feel more like a menu of hosting modes than one simple ladder. Lambda is easier to reason about if you want one serverless runtime and predictable pay-per-use economics. Azure Functions is more nuanced if you need orchestration, no-cold-start options, or Azure-specific deployment patterns. If you are just building a small backend or automation workflow, Lambda is usually the cleaner default. If your app depends on Durable Functions or Azure features, Azure Functions has the advantage.
AWS Lambda vs Azure Functions free tier, side by side
| AWS LambdaFTV 49 | Azure FunctionsFTV 46 | |
|---|---|---|
| Free requests / executionsAzure has separate grants by plan. | 1,000,000 requests per month | 1,000,000 executions per month on Consumption; 250,000 on-demand executions per month on Flex Consumption |
| Free compute grantBoth are per subscription/account style grants, but Azure splits by plan. | 400,000 GB-seconds per month | 400,000 GB-s per month on Consumption; 100,000 GB-s per month on Flex Consumption |
| HTTP response streaming / related extrasSkip comparison beyond what is shown. | 100 GiB per month beyond the first 6 MB per request | Not listed in the provided input |
| Additional storageAzure input here does not provide an equivalent storage quota. | 512 MB ephemeral storage included; extra billed separately | Not listed in the provided input |
After you outgrow the free tier
Both products use usage-based pricing after the free tier, but Lambda is more transparent in the provided data: it charges per million requests plus per GB-second, with extra fees for optional features like Provisioned Concurrency, Durable Functions, tenant isolation, and extra ephemeral storage. Azure Functions also stays usage-based for its core plans, but the input does not include concrete per-unit rates, so precise bill comparisons are not available here. For small builders, Lambda is easier to estimate from usage; Azure’s cost path depends more on which hosting mode and add-ons you choose.
Cost at real usage
| Usage | AWS Lambda | Azure Functions |
|---|---|---|
| 100k requests/mo, 100k GB-s/moLambda estimate uses the provided rates: $0.20 per million requests plus $0.0000166667 per GB-second. Azure rates were not provided in the input. | est. ~$1.87/mo | Contact sales / varies by usage |
| 1M requests/mo, 400k GB-s/moAssumes all usage stays within the listed free grants for each product. | Free (within tier) | Free (within tier) |
| 2M requests/mo, 500k GB-s/moLambda estimate adds overage beyond the free tier. Azure overage cannot be calculated from the provided data. | est. ~$11.87/mo | Contact sales / varies by usage |
Estimates, not quotes. Usage-based rates change - verify with the vendor's pricing page before committing.
When to pick each one
Pick AWS Lambda when…
- You want the simplest serverless free tier to understand and grow from.
- You expect to pay only for requests and execution time on a straightforward usage basis.
- You need additional Lambda-specific options like Provisioned Concurrency, Durable Functions, or tenant isolation later.
- You are already building around AWS services and want the compute layer to stay inside that ecosystem.
Pick Azure Functions when…
- You want Azure-native triggers, bindings, and deployment patterns from the start.
- You expect to use Durable Functions or Durable task scheduling for orchestration-heavy workflows.
- You want Flex Consumption with on-demand and Always Ready modes.
- You care about Premium plan features like no cold start or VNET access.
- You are already standardized on Microsoft Azure and want serverless compute to fit that stack.
Bottom line
For the most common builder case, AWS Lambda is the better default: the free tier is easy to understand, the paid model stays simple, and the route from prototype to production is clear. Azure Functions is the better choice when you already live in Azure or need its plan options, especially Durable Functions, Flex Consumption, or Premium features. If you just want serverless compute for a small backend or automation workflow, Lambda is the easier pick. If orchestration and Azure integration matter more, choose Azure Functions.
Read the full listings: AWS Lambda and Azure Functions. Scores use the FTV methodology at /ftv. Browse more head-to-heads on /compare, or see the top-ranked free tiers on /top.