Overview
Amazon RDS is the managed relational database service on AWS. You choose an engine (PostgreSQL, MySQL, MariaDB, SQL Server, Oracle or Db2), an instance class and storage, and AWS handles provisioning, backups, patching and failover. Multi-AZ deployments keep a standby in another Availability Zone, or two readable standbys for PostgreSQL and MySQL. Billing is per instance-hour (per second after a 10-minute minimum) plus storage and I/O, with Reserved Instances and Database Savings Plans for committed use.
Aurora is AWS's own MySQL- and PostgreSQL-compatible engine with distributed storage that grows automatically to 256 TiB, up to 15 read replicas and Global Database for cross-region reads. Aurora Serverless scales capacity in 0.5 ACU steps and can scale to 0 ACU when idle. Aurora DSQL is a separate serverless, distributed SQL service with an always-free monthly allowance.
AWS changed its free tier on 15 July 2025: new accounts now get sign-up credits and a time-limited Free plan instead of the old 12 months of 750 free micro-instance hours. The smallest RDS PostgreSQL instance (db.t4g.micro) costs $0.016/hr in us-east-1, roughly $12 a month before storage. Expect to use the AWS Pricing Calculator: storage, I/O, backups, data transfer and Multi-AZ all change the bill.
Pricing and plans
checked 28 Sept 2026| Plan | Price | What you get |
|---|---|---|
| RDS On-Demand | From $0.016/hr | db.t4g.micro (2 vCPU, 1 GiB) PostgreSQL Single-AZ in us-east-1; $0.032/hr Multi-AZ; storage from 20 GiB billed separately |
| RDS Reserved Instances | Custom | 1- or 3-year terms, up to 69% off On-Demand for steady workloads |
| Aurora Serverless | Per ACU-hour | Scales from 0 ACU in 0.5 ACU steps up to 256 ACUs; 1 ACU is about 2 GiB of memory |
| Aurora provisioned | Per instance-hour | Aurora Standard (pay per I/O) or I/O-Optimized (no I/O charges) |
| Aurora DSQL | Usage-based | Serverless distributed SQL; free each month up to 100k DPUs and 1 GiB storage |
What it does
- Six RDS engines
- PostgreSQL, MySQL, MariaDB, SQL Server, Oracle and Db2, including bring-your-own-media licensing for SQL Server.
- Multi-AZ high availability
- One standby in another AZ, or two readable standbys across three AZs, with automatic failover.
- Aurora Serverless
- Capacity measured in ACUs and billed per second, scaling from 0 ACU up to 256 ACUs.
- Aurora DSQL
- A serverless, distributed SQL database with an always-free tier of 100k DPUs and 1 GiB storage per month.
- Automated backups
- Automated backups, manual snapshots, cross-region backup copies and point-in-time restore.
- Zero-ETL integrations
- Replicate transactional data to Amazon Redshift for near real-time analytics without building pipelines.
Strengths and limitations
Strengths
- Widest engine choice, including commercial Oracle, SQL Server and Db2
- Deep integration with the rest of AWS (IAM, VPC, CloudWatch, Redshift)
- Aurora Serverless can scale to zero and up to large workloads
- Reserved Instances and Savings Plans for large discounts on steady workloads
- Regions worldwide, including the EU
Limitations
- Pricing has many parts (instance, storage, I/O, backups, transfer, CPU credits) and varies by region
- New accounts since 15 July 2025 get time-limited credits rather than the old 12-month free micro instance
- T3/T4g burstable instances bill CPU credits when average usage exceeds baseline
- Cross-AZ traffic between EC2 and RDS is charged at $0.01 per GB each way
Who it suits
Good for
- Teams already running on AWS
- Enterprises needing Oracle, SQL Server or Db2 as a managed service
- Large or regulated workloads needing Multi-AZ and cross-region options
- Spiky workloads on Aurora Serverless
Look elsewhere if
- Hobby projects wanting a free, simple, long-term database
- Small teams who want one flat monthly price
Pricing history
-
AWS Free Tier moves to credits for new accounts
Effective 2025-07-15: new AWS accounts get $100 in credits (up to $100 more) and a time-limited free plan instead of 12 months of 750 free micro-instance hours; older accounts keep the legacy free tier. Source ↗
Alternatives to Amazon RDS and Aurora
| Tool | From | Free option | Stages |
|---|---|---|---|
| Aiven Managed open-source data platform (PostgreSQL, MySQL, Kafka, Valkey, OpenSearch, ClickHouse) | $5/mo | Free tier | |
| Clever Cloud European managed PaaS | €6/mo | ||
| CockroachDB Cloud (Cockroach Continuum) Managed distributed SQL (PostgreSQL-compatible) | Usage-based | ||
| Convex Reactive backend and document database | $25/mo | Free tier | |
| Crunchy Bridge Managed PostgreSQL on AWS, Azure and GCP | $9/mo | ||
| Dragonfly Cloud Managed Redis-compatible in-memory data store | $36/mo |
Questions
Is Amazon RDS free?
Only within the AWS Free Tier. Since 15 July 2025, new accounts get $100 in credits plus up to $100 more for up to 12 months, and a Free plan covering micro instances; older accounts keep 750 hours a month of a micro instance for 12 months.
What is the cheapest Amazon RDS PostgreSQL instance?
db.t4g.micro (2 vCPU, 1 GiB) at $0.016 per hour Single-AZ in us-east-1, plus storage and backups.
Can Aurora scale to zero?
Yes. Aurora Serverless lists a starting capacity of 0 ACU and scales in 0.5 ACU increments.
What is the difference between RDS and Aurora?
RDS runs the standard engines on instances with attached storage; Aurora is AWS's own MySQL- and PostgreSQL-compatible engine with shared distributed storage, more replicas and serverless scaling.
Does data transfer between RDS and EC2 cost money?
It is free within the same Availability Zone; between AZs in the same region, standard EC2 transfer charges of $0.01 per GB in and out apply.
Sources read for this page