Serverless Pricing Comparison
Function-as-a-Service pricing across AWS Lambda, Google Cloud Functions, and Azure Functions. Costs scale with invocation count, execution duration, and allocated memory.
Base Pricing Components
| Component | AWS Lambda | GCP Cloud Functions | Azure Functions |
|---|---|---|---|
| Per invocation | $0.20 / 1M | $0.40 / 1M | $0.20 / 1M |
| Compute (GB-second) | $0.0000166667 | $0.0000025 | $0.000016 |
| CPU (GHz-second) | Included in GB-s | $0.00001 | Included in GB-s |
| Memory range | 128 MB - 10,240 MB | 128 MB - 32,768 MB | 128 MB - 14,336 MB |
| Max timeout | 15 minutes | 60 minutes (2nd gen) | 230 seconds (Consumption) |
Free Tier Limits (Monthly)
| Allowance | AWS Lambda | GCP Cloud Functions | Azure Functions |
|---|---|---|---|
| Free invocations | 1,000,000 | 2,000,000 | 1,000,000 |
| Free compute | 400,000 GB-s | 400,000 GB-s | 400,000 GB-s |
| Free tier type | Always free | Always free | Always free |
Monthly Cost Estimates by Invocation Count
Assuming 256 MB memory, 200ms average duration per invocation. Costs after free tier.
| Monthly Invocations | AWS Lambda | GCP Cloud Fn | Azure Functions |
|---|---|---|---|
| 1 million | $0.00 | $0.00 | $0.00 |
| 10 million | $10.55 | $7.60 | $10.12 |
| 50 million | $54.53 | $39.20 | $52.32 |
| 100 million | $109.53 | $78.80 | $105.12 |
| 500 million | $549.53 | $396.00 | $528.12 |
Estimates are approximate. GCP charges separately for CPU (GHz-s) and memory (GB-s). Actual costs depend on memory allocation, duration, and region.
Cold Start and Performance Considerations
Cold Start Latency
Cold starts add 100ms-10s depending on runtime and package size. Java and .NET have the longest cold starts. Python and Node.js are fastest. GCP Cloud Functions 2nd gen uses Cloud Run under the hood, with cold starts typically under 1s for lightweight functions.
Provisioned Concurrency
AWS Lambda Provisioned Concurrency keeps functions warm at $0.0000041667/GB-s (approximately $3/month per instance at 256 MB). Azure Premium Plan provides always-ready instances. This eliminates cold starts but adds a fixed monthly cost.
Networking Costs
Lambda in a VPC no longer incurs extra cold start time (since 2019). However, NAT Gateway costs ($0.045/hr + $0.045/GB processed) for internet access from VPC-attached functions can exceed the function costs themselves.
When Serverless Gets Expensive
At sustained high throughput (above 50M invocations/month with long durations), containers or VMs may be cheaper. The crossover point depends on duration and memory. Functions averaging over 1s with 512+ MB memory become expensive quickly.