object-key · shipping · also object key name, S3 object key

Object key

An object key is the name used to address an object within an object-storage bucket.

Related Observatory article: Object key on hesela.com

In S3, the case-sensitive key is the complete name, including prefixes and delimiters. Its limit is 1,024 bytes in UTF-8, not a fixed character count. [1]

The bucket supplies the key's namespace; a version ID additionally selects a stored version when S3 versioning applies. A key is not a checksum or a version identifier. [2]

In S3 general-purpose buckets, a slash can support folder-like presentation without making the key a filesystem path. S3 separately provides a hierarchical namespace for directory buckets; do not generalize the flat model to every bucket type. [3] [4]

ListObjectsV2 can percent-encode returned names with encoding-type=url. Treat that response representation separately from the key: report%252Ffinal decodes once to report%2Ffinal, not report/final. Check whether a client has already decoded the response before decoding it. [5] [6]

Relations

related

Object storage, Object key prefix, Object version ID, Entity tag

Advantages

• A bucket and exact key identify the object name independently of its presentation as folders. [2, 3]

Limitations

• Path normalization by a client can change the key sent to S3 when it contains standalone dot or dot-dot segments. [1]

Citations

1. Amazon S3: Naming objects, case, UTF-8 length and full keys (accessed 2026-10-28)
2. Amazon S3: Keys and version-specific identity (accessed 2026-10-28)
3. Amazon S3: Console folders and zero-byte marker objects (accessed 2026-10-28)
4. Amazon S3: Directory buckets and hierarchical namespaces (accessed 2026-10-28)
5. Amazon S3 API: ListObjectsV2, response encoding and fields (accessed 2026-10-28)
6. RFC 3986, section 2.4: When to Encode or Decode (accessed 2026-10-28)

JSON: /data/terms/object-key.json