Bucket naming guidelines

This page outlines the naming guidelines you should follow when creating buckets in Cloud Storage. To learn how to create a bucket, see the Creating storage buckets guide.

Bucket name requirements

Your bucket names must meet the following requirements:

  • Bucket names must contain only lowercase letters, numbers, dashes (-), underscores (_), and dots (.). Spaces are not allowed. Names containing dots require verification.
  • Bucket names must start and end with a number or letter.
  • Bucket names must contain 3-63 characters. Names containing dots can contain up to 222 characters, but each dot-separated component can be no longer than 63 characters.
  • Bucket names cannot be represented as an IP address in dotted-decimal notation (for example, 192.168.5.4).
  • Bucket names cannot begin with the "goog" prefix.
  • Bucket names cannot contain "google" or close misspellings, such as "g00gle".

Bucket name considerations

  • Bucket names reside in a single Cloud Storage namespace.

    This means that:

    • Every bucket name must be unique.
    • Bucket names are publicly visible.

    If you try to create a bucket with a name that already belongs to an existing bucket, Cloud Storage responds with an error message.

  • A bucket name can only be assigned during creation.

    You cannot change the name of an existing bucket. Instead, you should create a new bucket with the desired name and move the contents from the old bucket to the new bucket. See Moving and Renaming Buckets for a step-by-step guide.

  • Once you delete a bucket, anyone can reuse its name for a new bucket.

    The time it takes a deleted bucket's name to become available again is typically on the order of seconds; however, if you delete the project that contains the bucket, which effectively deletes the bucket as well, the bucket name may not be released for weeks or longer.

  • You can use a bucket name in a DNS record as part of a CNAME or A redirect.

    In order to do so, your bucket name should conform to standard DNS naming conventions. This means that your bucket name should not use underscores (_) or have a period next to another period or dash. For example, ".." is not valid within DNS names and neither is "-." or ".-".

See also the Naming Best Practices section, which includes recommendations about excluding proprietary information from bucket names.

Example bucket names

The following are examples of valid bucket names:

  • my-travel-maps
  • 0f75d593-8e7b-4418-a5ba-cb2970f0b91e
  • test.example.com (Requires verification of ownership for example.com)

The following are examples of invalid bucket names:

  • My-Travel-Maps (contains uppercase letters)
  • my_google_bucket (contains "google")
  • test bucket (contains a space)

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