The bytes come out with the AWS CLI: run aws s3 sync s3://bucket-name local-directory, which recursively copies every new and updated object down to a local folder. The caller needs s3:GetObject and s3:ListBucket. For the list of what is in the bucket, sign in to the Amazon S3 console, choose General purpose buckets, open the bucket, open the Management tab, and under Inventory configurations choose Create inventory configuration, then set Inventory scope, Destination, Frequency of Daily or Weekly, and Output format of CSV, Apache ORC or Apache Parquet, ticking Size, Last modified date and Storage class under Additional metadata fields. The first report can take up to 48 hours, and a weekly report is generated every Sunday UTC.
What it holds
Files of every kind held as objects in buckets, with key names, sizes, last modified dates, storage class and, where versioning is on, every version.
Find the size
S3 Storage Lens puts the figures in the Account snapshot on the S3 console Buckets page, and its default dashboard is updated daily. Its daily metrics report exports to a bucket in CSV or Parquet. Quote total bytes stored and total object count from there, plus the row count of the S3 Inventory report.
What to enter on the form
Amazon S3 in GB, and the year your company started using it. Seller form