I tried to see if tag contents are replicated when tagging objects with S3 replication

Hello.
I'm Omori from tech support.

First

The S3 replication documentation states the following:

・Replicating objects within and between regions

Live replication – Use live replication to automatically replicate newly created or updated objects as they are written to the source bucket.

I was curious whether object tagging operations are included in updates, so I decided to test it.

What I tried

Pattern 1: Setting up a replication rule after placing an object, then adding tags

Result: Neither the object nor the tags were replicated

I placed an object in the source bucket "omori-repmoto-0130"

The "test1.txt" object before rule creation has no tags set

Setting up the replication rule "omori-rep-test-0130"

After creating the rule, I added tags to the object in the source bucket

The object was not replicated to the destination bucket "omori-repsaki-0130"

Note: When creating the replication rule, you're asked if you want to replicate existing objects,
but I selected "No" and did not replicate existing objects

Pattern 2: Placing an object after setting up the replication rule, then adding tags

Result: First the object was replicated, and then the tag content was also reflected in the destination object

Placing a new object "test2.txt" in the source bucket

"test2.txt" has no tags set

The object "test2.txt" was replicated to the destination bucket

The destination object "test2.txt" also has no tags set

Setting tags on the source object "test2.txt"

The tags were propagated to the destination object "test2.txt"

Changing the tag content of the source object "test2.txt"

The tag content changes were propagated to the destination object "test2.txt"

Summary

When an object is replicated to the destination before tagging,
if you then add tags to the source object, it is recognized as an update,
and the tags are propagated to the object in the destination.

If you want tag information to be propagated, please refer to the behavior described above.

Additional Notes

・When replicating existing objects during replication rule creation, tag additions to those objects were propagated to the destination.

・For the replication rule setup procedure, please refer to the following blog:
I tried using Amazon S3's replication feature.

About Classmethod Operations, Inc.

We are the operations company of the Classmethod Group.

Our specialized teams in operations, maintenance development, support, information systems, and back office are a group of experts who provide everything from business delegation to problem solving and high value-added services through "mechanisms" that fully utilize IT and AI.

We are recruiting members for various positions.

If you are interested in our culture, mechanisms, and work styles that together realize "Operational Excellence" and "Work like yourself, live like yourself," please visit the Classmethod Operations, Inc. corporate website. *Name changed from Annotation Inc. in January 2026.