AWS Secrets Manager vs Parameter Store: Key Differences and Usage

AWS Secrets Manager is designed for managing sensitive secrets with automatic rotation and fine-grained access control, while Parameter Store is a simpler service for storing configuration data and less sensitive parameters. Use Secrets Manager for high-security secrets and Parameter Store for general configuration values.

Quick Comparison

This table summarizes the main differences between AWS Secrets Manager and Parameter Store.

Feature	Secrets Manager	Parameter Store
Purpose	Manage sensitive secrets with rotation	Store configuration data and parameters
Secret Rotation	Built-in automatic rotation support	No built-in rotation, manual only
Encryption	Always encrypted with AWS KMS	Encrypted optionally with AWS KMS
Cost	Charged per secret and API calls	Free tier available, charges for advanced parameters
Access Control	Fine-grained IAM policies	IAM policies, less granular
Max Size per Secret	Up to 64 KB	Up to 4 KB per parameter

Key Differences

Secrets Manager is focused on securely storing sensitive information like database credentials, API keys, and tokens. It offers automatic secret rotation, which means it can update secrets regularly without manual intervention, improving security. It always encrypts secrets using AWS Key Management Service (KMS) and provides detailed access control through IAM policies.

On the other hand, Parameter Store is a simpler service mainly used for storing configuration data such as application settings or feature flags. It supports encryption but does not provide automatic rotation. Parameter Store has a free tier for standard parameters, making it cost-effective for less sensitive data. It supports both plain text and encrypted parameters but with smaller size limits.

In summary, use Secrets Manager when you need strong security, automatic rotation, and detailed access control for secrets. Use Parameter Store for general configuration storage where cost and simplicity are priorities.

Code Comparison

Here is how you store and retrieve a secret using AWS Secrets Manager with the AWS SDK for Python (boto3):

python

import boto3

client = boto3.client('secretsmanager')

# Create a secret
response = client.create_secret(
    Name='MySecret',
    SecretString='{"username":"admin","password":"mypassword"}'
)

# Retrieve the secret
get_secret_value_response = client.get_secret_value(SecretId='MySecret')
secret = get_secret_value_response['SecretString']
print(secret)

Output

{"username":"admin","password":"mypassword"}

Parameter Store Equivalent

Here is how you store and retrieve a parameter using AWS Systems Manager Parameter Store with the AWS SDK for Python (boto3):

python

import boto3

ssm = boto3.client('ssm')

# Put a parameter
ssm.put_parameter(
    Name='/MyApp/DBPassword',
    Value='mypassword',
    Type='SecureString',
    Overwrite=True
)

# Get the parameter
response = ssm.get_parameter(Name='/MyApp/DBPassword', WithDecryption=True)
print(response['Parameter']['Value'])

Output

mypassword

When to Use Which

Choose Secrets Manager when you need to store highly sensitive secrets that require automatic rotation, detailed access control, and audit logging. It is ideal for database credentials, API keys, and tokens that must be regularly updated without downtime.

Choose Parameter Store when you need a cost-effective way to store configuration data or less sensitive secrets without rotation. It works well for application settings, feature flags, or secrets that do not require frequent updates.

Key Takeaways

Use Secrets Manager for sensitive secrets needing automatic rotation and strong security.

Parameter Store is best for general configuration and less sensitive data with lower cost.

Secrets Manager always encrypts secrets; Parameter Store encryption is optional.

Secrets Manager supports larger secret sizes and fine-grained access control.

Choose based on your security needs, cost constraints, and secret management complexity.