How Much Does a Mobile App Backend Cost on AWS? (2026)

Six service categories account for nearly all mobile backend spend. Most teams need all six. The proportions shift as you scale, but the categories stay the same.

API servers (compute)

Every mobile app needs somewhere to run application logic. This is usually EC2 instances, ECS containers, or Lambda functions handling REST or GraphQL requests from the app. At low scale this is a single small instance. At high scale it's an auto-scaling group behind a load balancer. Compute is typically the largest single line item — 30–45% of total backend spend.

Database

Most mobile apps need a relational database (PostgreSQL or MySQL via RDS) for structured user and content data, often paired with a cache (ElastiCache Redis) for sessions and frequently-read records. Database costs are almost always the second-largest category. RDS instances are priced per hour regardless of actual query load, so idle dev databases burn real money.

Push notifications

AWS SNS handles push notification delivery to APNs (iOS) and FCM (Android). The pricing model is favorable at small scale — $0.50 per million mobile push notifications — but the cost is rarely zero. Infrastructure supporting fan-out to large audiences (topic subscriptions, queues) adds to the bill.

Storage

S3 stores user-uploaded media, app assets, and backups. At $0.023/GB/month for standard storage, the raw storage cost is low until you have meaningful user-generated content. Data transfer out of S3 — the egress charge — is where the real cost hides. Without a CDN in front of S3, you pay $0.09/GB for every download.

Authentication

AWS Cognito handles sign-up, sign-in, and token management. It's free for the first 50,000 monthly active users (MAUs), then $0.0055 per MAU. At typical mobile DAU/MAU ratios, auth costs are negligible until you reach roughly 100K MAU — then they become a real line item.

CDN

CloudFront sits in front of your API and S3 assets to reduce latency for global users and cut egress costs from origin. CloudFront data transfer is cheaper than direct EC2 or S3 egress — $0.085/GB for the first 10 TB vs $0.09/GB from S3 origin. More importantly, CDN caching reduces the number of requests hitting your API servers and database.

The numbers below use AWS us-east-1 on-demand pricing as published in AWS documentation (2025). "Active users" means monthly active users making regular API requests — not registered accounts. Use the free mobile app backend calculator to adjust for your specific request volume, data transfer, and storage requirements.

1,000 active users — $200 to $300/mo

At this scale, infrastructure costs are modest. The $200–$300 range reflects configuration choices: single vs multi-AZ, log retention settings, and whether you're running dev/staging environments on the same account. Most waste at this tier comes from forgetting to shut down dev instances.

10,000 active users — $1,500 to $1,600/mo

This is where architectural choices start mattering. Adding Multi-AZ to RDS doubles the database cost but is necessary for any app with paying users. NAT Gateway costs grow with traffic volume — two AZs at 200GB processed adds $18/month in data processing fees alone. The upper end of the range ($1,600) reflects teams running separate staging environments and verbose logging.

100,000 active users — $3,500 to $4,000/mo

At 100K MAU, compute becomes the dominant cost. You're running an auto-scaling group of 3–6 instances, a production-grade database, and real CDN traffic. The specific numbers:

• EC2 auto-scaling group (4x t3.large average): $240/mo
• RDS db.t3.large, Multi-AZ, 200GB storage: $270/mo
• ElastiCache cache.t3.small: $27/mo
• CloudFront (5TB transfer) + S3 (200GB storage): $460/mo
• ALB + NAT Gateway (2TB NAT processed): $135/mo
• Cognito (100K MAU above free tier): $275/mo
• SNS (20M notifications): $10/mo
• CloudWatch, Route53, ACM, misc: $80/mo

Total baseline: roughly $3,500/mo. The $4,000 ceiling reflects high-media apps (video, audio) with large egress, read replicas for analytics queries, and multiple environments. Cognito becomes a meaningful expense here — $275/month for 100K MAU is real money, and it's the point where evaluating self-hosted auth starts making sense.

1,000,000 active users — $11,000 to $13,000/mo

At 1M MAU you're operating production infrastructure. Reserved instances are non-negotiable — staying on on-demand at this scale adds $3,000–$6,000/month compared to 1-year reserved pricing (AWS Reserved Instance pricing docs, 2025). Key cost drivers at this tier:

• EC2 fleet (12–20 instances, mix of on-demand + reserved): $1,200–$2,800/mo
• RDS db.r6g.large, Multi-AZ, read replica, 1TB storage: $900–$1,400/mo
• ElastiCache r6g.large cluster: $180/mo
• CloudFront (50TB transfer) + S3 (2TB): $4,500/mo
• ALB + NAT Gateway (20TB NAT processed): $1,100/mo
• Cognito (1M MAU): $5,225/mo
• SNS, SQS, messaging infrastructure: $200/mo
• CloudWatch, monitoring, misc: $400/mo

Cognito becomes the second-largest line item at 1M MAU. Many teams at this scale switch to self-hosted auth (Auth0 Business is cheaper at scale, Keycloak is free but requires ops overhead). Data transfer — the combination of CloudFront egress and NAT Gateway — often surprises teams. Read our guide on AWS bill structure for strategies to reduce egress costs before they compound.

AWS leads mobile backend adoption, but Azure and GCP are genuinely competitive — and cheaper for specific workloads. Here's how the three compare for the services that matter most to mobile apps.

GCP has a real cost advantage for mobile backends: Firebase Auth is unlimited and free, FCM push notifications are free, and GCP Sustained Use Discounts apply automatically without commitment — typically 20–30% for instances running full-time. For startups under 50K MAU, GCP often beats AWS on total infrastructure cost.

AWS wins on ecosystem maturity and operational tooling. If your team already uses AWS for other infrastructure, consolidating on AWS avoids cross-provider data transfer charges and reduces operational complexity. For a deeper look at the compute and storage pricing differences, see our reserved vs spot vs on-demand comparison which covers purchasing model discounts across all three providers.

Azure tends to be cost-competitive on database and storage pricing but has higher push notification costs and a less mature mobile SDK ecosystem compared to AWS Amplify or Firebase. It's a reasonable choice if your organization already has Microsoft licensing agreements or runs .NET backends.

Run your own numbers with the free mobile app backend calculator, which compares estimated costs across AWS, Azure, and GCP for your specific configuration.

Backend-as-a-Service platforms like Firebase, Supabase, and Appwrite bundle auth, database, storage, and push notifications into a single managed service. They eliminate ops overhead. The question is whether you pay for that convenience in dollars or lose it in flexibility.

Firebase cost vs self-hosted (AWS)

Firebase is cheaper at every scale up to roughly 50K–100K MAU. Below that threshold, the savings from Firebase's free tier and the avoided ops cost (engineering time managing infrastructure) make BaaS the financially rational choice. Above 100K MAU, the curves cross — and at 500K MAU, Firebase can cost more than a well-tuned AWS setup.

The crossover point depends on your data model. Apps with heavy Firestore read/write patterns face Firebase costs that scale with document operations, not just users. A social feed app reading 50 documents per session per user crosses the break-even point much earlier than a simple CRUD app. Self-hosted PostgreSQL on RDS has flat per-hour pricing regardless of query volume.

The hidden cost of BaaS that most comparisons ignore: vendor lock-in risk. Firebase's data model (Firestore document structure, real-time listeners) is deeply coupled to the platform. Migrating off at 500K MAU is a multi-month engineering project. Self-hosted from day one avoids that constraint entirely.

These five tactics reduce mobile backend costs without degrading performance or reliability. They apply regardless of scale, though the dollar impact grows as you grow.

1. Cache aggressively at the API layer

Most mobile API endpoints serve data that doesn't change on every request. User profiles, product catalogs, content feeds — these are read far more often than they're updated. Adding Redis (ElastiCache) in front of your database and caching responses for even 30–60 seconds eliminates 60–80% of database reads for read-heavy workloads. A cache.t3.micro at $13/month can defer a database upgrade that would cost $100–$200/month.

2. Put CloudFront in front of everything

CDN is not just for static assets. CloudFront can cache API responses, serve app assets from edge locations, and cut S3 egress costs. Direct S3 data transfer costs $0.09/GB; CloudFront costs $0.085/GB for the first 10TB and drops to $0.02/GB at high volume. More importantly, cached responses at the edge never hit your origin servers at all. For a mobile app with global users, CDN reduces both cost and latency in one move.

3. Right-size your database immediately

RDS instances are the most over-provisioned resource in mobile backends. Engineers provision for projected peak load, then never revisit the instance size. A db.t3.large at $130/mo may be doing the work of a db.t3.small at $32/mo. Check RDS CloudWatch metrics: if CPU utilization averages below 20% and FreeableMemory stays above 60%, you're paying for headroom you don't need. Downsizing takes 20 minutes with a maintenance window.

4. Use Lambda for infrequent API endpoints

Not every API endpoint runs constantly. Account deletion, password reset, report generation, bulk export — these happen rarely but often run on always-on EC2 instances. Moving low-frequency endpoints to Lambda eliminates the idle compute cost. Lambda pricing is $0.20 per million requests plus $0.0000166667 per GB-second of execution time. For an endpoint called 10,000 times per month using 256MB for 500ms, that's $0.23/month vs $30/month for a dedicated t3.small. See our guide on choosing the right compute purchasing model for how to blend Lambda, spot, and reserved instances in a cost-efficient architecture.

5. Buy reserved instances for steady-state compute

Once your API server fleet stabilizes — meaning you know roughly how many instances you need at baseline — convert that baseline to 1-year reserved instances. AWS 1-year reserved pricing saves 30–40% over on-demand for the same instance type (AWS Reserved Instance pricing docs, 2025). On a $400/mo EC2 bill, that's $120–$160/month saved with zero architectural change. Use on-demand or spot for auto-scaling above the baseline; reserve the floor. This single change is often the highest-leverage cost optimization available to a growing mobile app.