Bucket Restrictions and Limitations

A bucket is owned by the AWS account that created it. Bucket ownership is not transferable. When you create a bucket, you choose the Region to create the bucket in. After you create a bucket, you can't change its Region.

By default, you can create up to 100 buckets in each of your AWS accounts. If you need additional buckets, you can increase your account bucket limit to a maximum of 1,000 buckets by submitting a service limit increase. There is no difference in performance whether you use many buckets or just a few. For information about how to increase your bucket limit, see AWS Service Limits in the AWS General Reference.

Reusing Bucket Names
If a bucket is empty, you can delete it. After a bucket is deleted, the name becomes available for reuse. However, after you delete the bucket, you might not be able to reuse the name for various reasons. For example, when you delete the bucket and the name becomes available for reuse, another account, might create a bucket with the name. Additionally, some time may pass before you can reuse the name of a deleted bucket. If you want to use the same bucket name, we recommend that you don't delete the bucket.

Objects and Buckets
There is no limit to the number of objects that you can store in a bucket. You can store all of your objects in a single bucket, or you can organize them across several buckets. However, you can't create a bucket from within another bucket.

Bucket Operations
The high-availability engineering of Amazon S3 is focused on get, put, list, and delete operations. Because bucket operations work against a centralized, global resource space, it is not appropriate to create or delete buckets on the high-availability code path of your application. It is better to create or delete buckets in a separate initialization or setup routine that you run less often.

Bucket Naming and Automatically Created Buckets
If your application automatically creates buckets, choose a bucket naming scheme that is unlikely to cause naming conflicts. Ensure that your application logic will choose a different bucket name if a bucket name is already taken.

Rules for Bucket Naming

After you create an S3 bucket, you can't change the bucket name, so choose the name wisely.

Important
On March 1, 2018, we updated our naming conventions for S3 buckets in the US East (N. Virginia) Region to match the naming conventions that we use in all other worldwide AWS Regions. Amazon S3 no longer supports creating bucket names that contain uppercase letters or underscores. This change ensures that each bucket can be addressed using virtual host style addressing, such as https://myawsbucket.s3.us-east-1.amazonaws.com. We highly recommend that you review your existing bucket-creation processes to ensure that you follow these DNS-compliant naming conventions.

Rules
The following are the rules for naming S3 buckets in all AWS Regions:

• Bucket names must be unique across all existing bucket names in Amazon S3.
• Bucket names must comply with DNS naming conventions.
• Bucket names must be at least 3 and no more than 63 characters long.
• Bucket names must not contain uppercase characters or underscores.
• Bucket names must start with a lowercase letter or number.
• Bucket names must be a series of one or more labels. Adjacent labels are separated by a single period (.). Bucket names can contain lowercase letters, numbers, and hyphens. Each label must start and end with a lowercase letter or a number.
• Bucket names must not be formatted as an IP address (for example, 192.168.5.4).
• When you use virtual hosted–style buckets with Secure Sockets Layer (SSL), the SSL wildcard certificate only matches buckets that don't contain periods. To work around this, use HTTP or write your own certificate verification logic. We recommend that you do not use periods (".") in bucket names when using virtual hosted–style buckets.

Legacy Non–DNS-Compliant Bucket Names

Beginning on March 1, 2018, we updated our naming conventions for S3 buckets in the US East (N. Virginia) Region to require DNS-compliant names.

The US East (N. Virginia) Region previously allowed more relaxed standards for bucket naming, which could have resulted in a bucket name that is not DNS-compliant. For example, MyAWSbucket was a valid bucket name, even though it contains uppercase letters. If you try to access this bucket by using a virtual-hosted–style request (https://MyAWSbucket.s3.us-east-1.amazonaws.com/yourobject), the URL resolves to the bucket myawsbucket and not the bucket MyAWSbucket. In response, Amazon S3 returns a "bucket not found" error. For more information about virtual-hosted–style access to your buckets, see Virtual Hosting of Buckets.

The legacy rules for bucket names in the US East (N. Virginia) Region allowed bucket names to be as long as 255 characters, and bucket names could contain any combination of uppercase letters, lowercase letters, numbers, periods (.), hyphens (-), and underscores (_).

The name of the bucket used for Amazon S3 Transfer Acceleration must be DNS-compliant and must not contain periods ("."). For more information about transfer acceleration, see Amazon S3 Transfer Acceleration.