Edit IAM policies

A policy is an entity that, when attached to an identity or resource, defines their permissions. Policies are stored in AWS as JSON documents and are attached to principals as identity-based policies in IAM. You can attach an identity-based policy to a principal (or identity), such as an IAM user group, user, or role. Identity-based policies include AWS managed policies, customer managed policies, and inline policies. You can edit customer managed policies and inline policies in IAM. AWS managed policies cannot be edited. The number and size of IAM resources in an AWS account are limited. For more information, see IAM and AWS STS quotas.

It's generally better to use customer managed policies instead of inline policies or AWS managed policies. AWS managed policies usually provide broad administrative or read-only permissions. Inline policies can't be reused on other identities or managed outside of the identity where they exist. For the greatest security, grant the least privilege, which means granting only the permissions required to perform specific job tasks.

When you create or edit IAM policies, AWS can automatically perform policy validation to help you create an effective policy with least privilege in mind. In the AWS Management Console, IAM identifies JSON syntax errors, while IAM Access Analyzer provides additional policy checks with recommendations to help you further refine your policies. To learn more about policy validation, see IAM policy validation. To learn more about IAM Access Analyzer policy checks and actionable recommendations, see IAM Access Analyzer policy validation.

You can use the AWS Management Console, AWS CLI, or AWS API to edit customer managed policies and inline policies in IAM. For more information about using AWS CloudFormation templates to add or update policies, see AWS Identity and Access Management resource type reference in the AWS CloudFormation User Guide.