Softwr

Cloud · head to head

Lambda (AWS Serverless) vs Fly.io

Lambda (AWS Serverless) logo

Lambda (AWS Serverless)

Cloud

Run code without thinking about servers

From
Free
Rated
-
Full reviewWebsite
Fly.io logo

Fly.io

Cloud

Deploy web applications globally

From
$29/month
Rated
-
Full reviewWebsite

The short version

  • Only Lambda (AWS Serverless) has a free tier, so it costs nothing to try first.
  • Each has a real cost: Lambda (AWS Serverless) billed on two axes at once, $0.20 per million requests plus $0.0000166667 per GB-second of duration, so memory settings change the bill as much as traffic does; Fly.io egress is priced by destination region, from $0.02 per GB in North America and Europe to $0.12 per GB for Africa and India, so the same traffic costs six times more depending on where users are
  • They diverge on capability: Lambda (AWS Serverless) covers Function-as-a-Service, Fly.io covers Global deployment.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Lambda (AWS Serverless) and Fly.io actually diverge.

Attributes where Lambda (AWS Serverless) and Fly.io differ
AttributeLambda (AWS Serverless)Fly.io
Starting priceFree$29/month
Free tierYesNo
PlatformsWeb, ApiWeb, Api, Docker
Founded20142020

Identical on both: pricing model (usage-based), user rating (Not yet rated), category (Cloud).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Lambda (AWS Serverless)

  • Function-as-a-Service
  • Event-driven execution
  • Pay-per-use
  • Multiple languages
  • Concurrency limits
  • Dead Letter Queues
  • Environment variables
  • API Gateway

Only in Fly.io

  • Global deployment
  • Docker support
  • Postgres databases
  • Redis support
  • Health checks
  • Backups
  • Monitoring
  • Docker

Both cover

  • Auto-scaling
  • Cloud deployment
  • Web support

What people use each for

The jobs each tool is most often brought in to do.

Lambda (AWS Serverless)

  • Event-driven functions without managing serversnot Fly.io
  • API backends behind API Gatewaynot Fly.io
  • Processing S3, DynamoDB, SQS and Kinesis eventsnot Fly.io
  • Scheduled jobs without a always-on instancenot Fly.io
  • Edge compute through Lambda@Edgenot Fly.io

Fly.io

  • Deploying containerised applications close to users across regionsnot Lambda (AWS Serverless)
  • Running full stack apps and databases on managed machinesnot Lambda (AWS Serverless)

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Lambda (AWS Serverless)

  • Billed on two axes at once, $0.20 per million requests plus $0.0000166667 per GB-second of duration, so memory settings change the bill as much as traffic does
  • Provisioned concurrency, used to avoid cold starts, is charged separately at $0.0000041667 per GB-second whether or not the function runs
  • Ephemeral storage beyond the included 512 MB is metered
  • Lambda@Edge costs $0.60 per million requests, three times the standard request rate
  • VPC use and cross-region data transfer carry EC2 charges on top

Fly.io

  • Egress is priced by destination region, from $0.02 per GB in North America and Europe to $0.12 per GB for Africa and India, so the same traffic costs six times more depending on where users are
  • Stopped machines still bill at $0.15 per GB of root filesystem a month, so a paused service is not a free one
  • Volumes are billed on provisioned capacity rather than usage, at $0.15 per GB a month
  • Reservation discounts of 40% require paying a year up front, from $36 to $1,440
  • Fly Kubernetes is a separate $75 a month per cluster
  • Dedicated IPv4 addresses are $2 a month each

Pricing, plan by plan

Lambda (AWS Serverless)

Free
  • Free TierFree
    • 1M free requests/month
    • 400,000 GB-seconds/month
    • Always free

Fly.io

$29/month
  • Pay-as-You-Go$null/mo
    • Micro VMs and persistent storage charged by usage
    • FlyCTL CLI
    • Unlimited users and organizations
  • Serious Support$29/month
    • Access to dedicated engineering team
    • All Pay-as-You-Go features
  • Machine Reservation Blocks$null/mo
    • 40% discount on machine usage
    • Requires upfront payment for savings
  • Compliance Package$99/month
    • HIPAA compliance
    • BAAs
    • SOC2 documentation

Which should you pick?

Choose Lambda (AWS Serverless) if

  • You need function-as-a-service.
  • You want to start without paying.
  • You work on Web, Api.
  • You also want event-driven execution.
Lambda (AWS Serverless) review

Choose Fly.io if

  • You need global deployment.
  • You work on Web, Api, Docker.
  • You also want docker support.
Fly.io review

Questions people ask

Is Lambda (AWS Serverless) or Fly.io better?
Neither clearly leads. Lambda (AWS Serverless) starts at Free and Fly.io at $29/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Lambda (AWS Serverless) or Fly.io?
Lambda (AWS Serverless) has a free tier; the other does not. Paid plans start at Free for Lambda (AWS Serverless) and $29/month for Fly.io.
Does Lambda (AWS Serverless) or Fly.io run on more platforms?
Lambda (AWS Serverless) runs on Web, Api. Fly.io runs on Web, Api, Docker.
Can I use Lambda (AWS Serverless) for free?
Yes. Lambda (AWS Serverless) has a free tier, so you can try it without paying. Fly.io starts at $29/month.
What is Lambda (AWS Serverless) best used for?
Lambda (AWS Serverless) is most often used for event-driven functions without managing servers, api backends behind api gateway, processing s3, dynamodb, sqs and kinesis events, scheduled jobs without a always-on instance. Of those, event-driven functions without managing servers and api backends behind api gateway are not what Fly.io is typically brought in for.
What can Lambda (AWS Serverless) do that Fly.io cannot?
Lambda (AWS Serverless) covers Function-as-a-Service, Event-driven execution, Pay-per-use, Multiple languages. Fly.io covers Global deployment, Docker support, Postgres databases, Redis support. Both handle Auto-scaling, Cloud deployment, Web support.

Answered from the vendors’ own pages

Lambda (AWS Serverless): Is there a free tier for AWS Lambda?

Yes. AWS Lambda offers a free tier including 1 million requests per month, 400,000 GB-seconds per month, and 100 GB monthly response streaming.

Source
Fly.io: Is there a free tier for Fly.io?

Fly.io does not advertise a free tier. The base plan is pay-as-you-go with usage-based pricing for Micro VMs and persistent storage. All users get FlyCTL CLI, unlimited organizations, private networking, SSO, ACLs, and scoped tokens.

Source
Lambda (AWS Serverless): How is AWS Lambda charged?

Lambda charges $0.20 per million requests. Duration charges are $0.0000166667 per GB-second for x86 (up to 6 billion GB-seconds/month in US East Ohio with tiered pricing). Ephemeral storage over the included 512 MB costs $0.0000000309 per GB-second. Provisioned Concurrency costs $0.0000041667 per GB-second with a 5-minute minimum.

Source
Fly.io: How much does Fly.io Serious Support cost?

Serious Support costs 29 USD per month and provides access to a dedicated engineering team while maintaining all pay-as-you-go features for Micro VMs and storage.

Source
Lambda (AWS Serverless): What are Lambda Durable Functions pricing?

Lambda Durable Functions include operations at $8.00 per million (start execution, steps, waits). Data written costs $0.25 per GB. Data retention is $0.15 per GB-month with configurable 1-90 day retention (default 14 days).

Source
Fly.io: What does Fly.io Compliance Package include?

The Compliance Package is 99 USD per month and includes HIPAA compliance, BAAs, and SOC2 documentation for organizations requiring compliance certifications.

Source
Fly.io: Does Fly.io offer discounts for upfront commitment?

Yes, Fly.io offers Machine Reservation Blocks with 40% discount on machine usage. This requires upfront payment but applies savings on infrastructure costs.

Source
Share

Related pages

More on Lambda (AWS Serverless)

More on Fly.io

Keep looking

Other head to heads