Updated on 2026-08-21 GMT+08:00

Adding Tags to an Object

Tag Rules

OBS offers object tags for you to classify objects in buckets. You can tag an object when you upload it to a bucket or after it is stored in the bucket.

An object tag is a key-value pair. To use tags, follow the rules below:

An object can have up to 10 tags.
A tag key:
- Must be unique if there are multiple tags specified for an object.
- Can be up to 36 characters long. It must be case sensitive and unique and cannot start or end with a space. It cannot be left blank and cannot contain the following special characters: , / | < > = * \
A tag value:
Can be up to 255 characters long. It must be case sensitive and cannot start or end with a space. It can be left blank, but cannot contain the following special characters: , / | < > = * \

Important Notes

Object tags are now in open beta testing, and you can use them for free. Once the testing period is over, you will be billed for using object tags.
To read or write object tags, you must have required permissions. Such permissions can be granted using bucket policies. By default, only the object owner can read or write the object's tags.
During cross-region replication, tags of source objects are not copied.
Tags cannot be added to files in parallel file systems.

Scenarios

Specifying object tags in a lifecycle rule

You can use a filter in a lifecycle rule to target only a set of objects. A filter can be defined based on an object name prefix, an object tag, or both. For example, you can configure a lifecycle rule to delete objects with prefix texta/ and tag key1/value1 or key2/value2 120 days after their creation.

<LifecycleConfiguration>
    <Rule>
        <ID>sample-rule</ID>  
        <Filter>
            <And>
                <Prefix>texta/</Prefix>
                <Tag>
                    <Key>key1</Key>
                    <Value>value1</Value>
                </Tag>
                <Tag>
                    <Key>key2</Key>
                    <Value>value2</Value>
                </Tag>
            </And>
        </Filter>
        <Status>Enabled</Status>
        <Expiration>
            <Days>120</Days>
        </Expiration>
    </Rule>
</LifecycleConfiguration>

Ways to Add Object Tags

You can use OBS Console or APIs to add tags to an object.

Using OBS Console

On OBS Console, you can add tags to an object when uploading it (see Using OBS Console). You can also add tags to an existing object, as described in the following:

In the navigation pane of OBS Console, choose Buckets.
In the bucket list, click the desired bucket. The Objects page is displayed.
In the object list, click the name of the object you want to add tags to.
On the object details page, choose Tags > Add Tag.

In the Add Tag dialog box, enter a tag key and a tag value.

**Table 1** Parameters for configuring a tag
Parameter	Description
Tag key	Key of a tag, which must be unique and cannot be left blank. You can customize a tag or choose one predefined on TMS. A tag key: Must be unique if there are multiple tags specified for an object. Can be up to 36 characters long. It must be case sensitive and unique and cannot start or end with a space. It cannot be left blank and cannot contain the following special characters: *, / \| < > = \**
Tag value	Value of a tag, which can be repetitive or left blank. A tag value: Can be up to 255 characters long. It must be case sensitive and cannot start or end with a space. It can be left blank, but cannot contain the following special characters: *, / \| < > = \**