European alternatives to Amazon S3

Amazon S3 is the object store that defined the category. Files go into buckets addressed by key, durability is quoted at eleven nines, and storage classes from Standard down to Glacier Deep Archive trade retrieval time for cost. Its real significance is the API: the S3 protocol became the lingua franca of object storage, and most tooling speaks it whether or not AWS is underneath.

That ubiquity cuts both ways for lock-in. Because competitors implement the S3 API, moving the interface is usually trivial — the client library and endpoint change, the code does not. What is expensive is the data itself: egress is billed per gigabyte, so a large bucket costs real money simply to read out once, and the bill grows with the archive. Bucket policies, IAM roles, lifecycle rules, versioning and event notifications into Lambda also have to be rebuilt, and those are AWS-shaped rather than S3-shaped.

Amazon S3 is part of Amazon Web Services, from Amazon.com, Inc. The European alternatives below both speak the S3 API and compete chiefly on egress pricing and EU jurisdiction.