How we rank: Object storage (S3-compatible)
The Score (0–100) is a weighted sum of the factors below. Each factor is the weighted average of its metrics; each metric is calculated from one published fact. Missing facts score zero, and a service is ranked only when enough of its Score is backed by facts.
A service is ranked only when at least 70% of its Score is backed by verified facts.
← Best S3-Compatible Object Storage 2026: Cloud Storage APIs Compared
Price 35%
The pay-as-you-go price of the standard (hot) storage class per GB-month for a US or EU region at the first volume tier, as printed on the official pricing page or in the provider's official machine-readable price file: $0 scores 100, $0.03 or more scores 0 (weight 3). A price per TB-month is divided by 1,000, a price per GiB by 1.073741824 and per TiB by 1,099.511627776; an hourly price counts only if the page itself states the monthly equivalent. A price without a stated period, a price drawn only by a script or a price in a currency chosen by our visitor location stays empty. Also the price per GB of data transfer out to the internet beyond any free allowance: $0 scores 100, $0.10 or more scores 0, and a provider that states egress is free gets $0 (weight 2). Also a permanent free tier of storage (weight 1); a trial or one-time credit does not count.
| Metric | Rule |
|---|---|
| Storage price per GB-month (standard class) | Linear from 0 (100) to 0.03 (0) — lower is better |
| Egress price per GB (to the internet) | Linear from 0 (100) to 0.1 (0) — lower is better |
| Permanent free tier | Yes = 100, No = 0 |
API and features 20%
Compatibility with the Amazon S3 API, so existing tools and SDKs work (weight 2); the number of regions or data-centre locations where the provider offers object storage, on a logarithmic scale up to 30 (weight 2); object versioning (weight 1) and lifecycle rules that expire or move objects automatically (weight 1). Features in preview or beta do not count.
| Metric | Rule |
|---|---|
| S3 API compatible | Yes = 100, No = 0 |
| Regions (provider's count) | Logarithmic, full score at 30 |
| Object versioning | Yes = 100, No = 0 |
| Lifecycle rules | Yes = 100, No = 0 |
Data protection 25%
Object Lock or another documented way to make objects immutable (WORM) for a retention period, which protects backups from ransomware and accidental deletion (weight 2); encryption of stored data at rest (weight 1); and an independent SOC 2 audit or ISO 27001 certification of the provider (weight 2).
| Metric | Rule |
|---|---|
| Object Lock (immutable storage) | Yes = 100, No = 0 |
| Encryption at rest | Yes = 100, No = 0 |
| SOC 2 or ISO 27001 | Yes = 100, No = 0 |
Reliability and trust 20%
The monthly uptime percentage in the provider's published SLA document for the standard storage class, on a straight line from 99% (0 points) to 100% (100 points) (weight 2); availability or durability figures from marketing pages are not an SLA and do not count. Also a public status page (weight 1) and how long the company has been running: 20 years or more scores 100 (weight 1).
| Metric | Rule |
|---|---|
| Uptime SLA | Linear from 99 (0) to 100 (100) |
| Public status page | Yes = 100, No = 0 |
| Founded | Full score at 20+ years |