What are the S3 bucket naming rules?

An S3 bucket name must be 3 to 63 characters, lowercase letters, digits, hyphens and dots only, start and end with a letter or digit, and must not be formatted as an IP address. This tool emits lowercase hyphen-separated names within those limits so they are DNS-compatible and valid globally.

How are Lambda function names different?

A Lambda function name allows letters in any case, digits, hyphens and underscores, up to 64 characters, and may not contain dots or spaces. The generator therefore produces mixed-segment names without the dot restriction that S3 has.

What about RDS instance identifiers?

An RDS DB instance identifier is 1 to 63 characters, must start with a letter, contain only lowercase letters, digits and hyphens, and may not end with a hyphen or contain two consecutive hyphens. The tool enforces all of these.

Are S3 bucket names globally unique?

Real S3 bucket names share a single global namespace, so a real name must be unique across all AWS accounts. These are example names for templates and tests — verify availability before using one for a real bucket.

Does the tool call AWS or any server?

No. Every name is generated locally in your browser with no network calls and no AWS credentials, so nothing you generate is transmitted or checked against AWS.

AWS Resource Name Generator

Names each AWS service will accept

AWS validates resource names differently per service, and a name that is valid for Lambda may be rejected by S3. The AWS Resource Name Generator builds identifiers that satisfy the specific rules for S3 buckets, Lambda functions and RDS instances, so the names you drop into a Terraform module or CloudFormation template pass validation on the first apply.

How it works

The tool keeps a small rule set per service and shapes the name to fit it. For an S3 bucket it lowercases everything, allows only [a-z0-9-], keeps the length between 3 and 63, ensures the first and last characters are alphanumeric, and rejects anything shaped like an IP address. For a Lambda function it allows mixed case with [A-Za-z0-9-_] up to 64 characters and no dots. For an RDS instance it forces a leading letter, allows [a-z0-9-], forbids trailing hyphens and double hyphens, and caps the length at 63.

Each candidate is built from word lists joined by hyphens (or underscores for Lambda), sanitized to the allowed character set, then checked against the service’s constraints before being shown. An optional environment suffix such as -prod is appended within the length limit.

Tips and example

S3: acme-analytics-logs — globally namespaced, so confirm availability before real use.
Lambda: acme-order-processor or acme_order_processor — underscores allowed, dots not.
RDS: acme-orders-db — must start with a letter and must not end with a hyphen.
Encode the environment in the name (for example -staging) so resources are easy to identify in the console and in cost reports.
All names are synthetic; verify real-world uniqueness and policy compliance before deploying.