S3 Versioning

Versioning keeps every version of an object so you can recover from accidental overwrites and deletes.

Versioning makes a bucket keep a full history of each object. When you overwrite or delete an object, the old version is retained instead of being lost.

How it behaves

  • Each version gets a unique version ID.
  • Deleting an object adds a delete marker rather than removing data; you can restore the previous version.
  • Once enabled, versioning can be suspended but not fully turned off.

Why it matters

Versioning protects against human error and ransomware. Combined with MFA Delete, it makes destroying data require a second factor. Remember that keeping many versions increases storage cost — pair it with a lifecycle rule to expire old versions.

Example

Example · bash
# Turn on versioning for a bucket
aws s3api put-bucket-versioning \
  --bucket my-app-assets \
  --versioning-configuration Status=Enabled

# List all versions of the objects
aws s3api list-object-versions --bucket my-app-assets \
  --query "Versions[].[Key,VersionId,IsLatest]" --output table

When to use it

  • A developer accidentally overwrites a critical config file in S3 and recovers the previous version within minutes using S3 versioning.
  • A compliance team enables versioning on an S3 bucket so every change to legal documents is preserved and traceable for audits.
  • A CI/CD pipeline uploads build artifacts to a versioned bucket, allowing rollback to any prior build artifact by referencing its version ID.

More examples

Enable Versioning on a Bucket

Turns on versioning for a bucket so every PUT or DELETE creates a new version rather than overwriting the object.

Example · bash
aws s3api put-bucket-versioning \
  --bucket my-bucket \
  --versioning-configuration Status=Enabled

List All Versions of an Object

Lists every stored version of a specific object with timestamps, so you can identify which version to restore.

Example · bash
aws s3api list-object-versions \
  --bucket my-bucket \
  --prefix config/app.json \
  --query 'Versions[].{VersionId:VersionId,Modified:LastModified,Latest:IsLatest}' \
  --output table

Restore a Previous Version

Restores an older object version by copying it over the current one, effectively rolling back without deleting history.

Example · bash
# Copy the old version back as the current version
aws s3api copy-object \
  --bucket my-bucket \
  --copy-source my-bucket/config/app.json?versionId=abc123xyz \
  --key config/app.json

Related

aws s3 introaws s3 storage classes

Discussion

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