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Update Custom Amazon S3 Metadata

Each File stored on Amazon S3 (Object) is associated with a key, and metadata.  Metadata or Headers  is a set of Key - Value pairs. Metadata provides some basic and important details about the file.

Amazon S3 allows you to set the Metadata on S3 Objects at the time of uploading the Objects. S3 does not allow you to modify the Objects Metadata after uploading the Objects. To modify the Metadata for existing S3 Objects, the only way is to make a copy of the Object and set the Metadata. If you are a software programmer, you can use PUT Object - Copy S3 API in your software program to do this and set metadata with the request using same Object Key.

You can update the Metadata of Amazon S3 Objects using Bucket Explorer User Interface very easily, using point and click, if you are not a software programmer. Bucket Explorer internally can make copy of Objects for you and you do not need to worry about doing all that work and writing any software program for that.

There are two types of metadata for files on S3.

1. System metadata : System metadata is used and processed by Amazon S3.
2. User metadata : User metadata or custom header is specified by you. Amazon S3 simply stores it and passes it back to you when you ask for it.

You can also change the Storage-Class of an object while updating metadata.

Note: Metadata size is limited to 2k bytes for the total length of all values and keys.
In Bucket Explorer, you can find more options through which you can update user metadata or custom headers:
  1. Right click on the selected S3 file in object panel and choose Update Metadata option.
  2. Right click on the selected S3 file in object panel and choose Properties and you will find the list of custom headers below of the panel. You can update metadata directly in properties window.
    OR
    Select an S3 file, click on Properties icon in object toolbar and you will find the list of custom headers at below the panel. You can update metadata directly in properties window.
  3. You can also update Storage Type and Server Side Encryption in properties window. You need to select the checkbox of Storage Type to set an object as Reduce Redundancy Storage (RRS) whereas select the checkbox of Server Side Encryption to protect sensitive data.
  1. Right click on the selected file in local file panel and choose Upload with custom header .
    Note : This process is used to Upload Files and Folders with custom headers or Metadata. You can add or remove metadata from here- How to upload files on Amazon S3 with custom header/ metadata using Bucket Explorer?
  2. You can set bucket default metadata and headers to add a specific metadata on all newly uploaded files in a specific bucket- How to set default Amazon S3 Metadata on bucket?

When you start updating metadata using any of the above options from 1 to 3, you can see a window of update Metadata that shows the properties and their values, if properties are present.

List of Properties displayed in update Metadata window are:

Sr. No.
Properties
Sr. No. Properties
1 Object key 9 ID-2
2 Date 10 request-ID
3 Size 11 Version-ID [1]
4 Last Modified 12 bucketexplorer-md5
5 Etag 13 bucketexplorer-sha1
6 Owner Name 14 bucketexplorer-filelastmodifieddate [2]
7 Owner ID 15 md5-hash
8 Bucket 16 Storage-class

You can also see the list of user metadata attributes below the properties list, which can be updated using Add, Edit and Remove options as per your requirement.

How to Add a New Metadata:

  1. Click on Add button in Update metadata window.
  2. It will display  Add Metadata box with key and value text box.
  3. Enter key and value .
  4. Click on OK button.
  5. It will Close the Add Metadata box.
  6. Newly added metadata will be listed in the Metadata attributes table.

How to Edit Existing Metadata:

  1. Select the existing user metadata and click on Edit button.
  2. It will display the Edit Metadata box with key label and value text box.
  3. Enter new value. Here,  key can’t be edited.
  4. Click on OK button.
  5. It will close the  Edit Metadata box.
  6. Edited user metadata will be updated in Metadata attributes table.

How to Remove Existing Metadata:

  1. Select the existing user metadata and click on Remove button.
  2. Selected Metadata will be removed from the Metadata attributes list.

Set Storage-Class as RRS (Reduced Redundancy Storage):

  • Enable the check box named Use reduced Redundancy Storage . It will set the Storage class to REDUCED_REDUNDANCY for that object.
  • To change the storage class to STANDARD , you need to disable the same check box.

On Update metadata window, click on Save button to save the changes of user Metadata and click on Cancel button to cancel the changes

NOTE: Bucket Explorer also allows you to update Amazon S3 Metadata in batch/ bulk. You can update Metadata of all objects in the selected bucket or you can also update Metadata for all the selected objects at once.

See step by step tutorial: How to update Amazon S3 Metadata in batch/ bulk?
See Video demo: How to update Metadata on batch/ bulk of files on Amazon S3?


  • Version-ID : It combines with the key to uniquely identify the object in the Bucket.
  • bucketexplorer-filelastmodifieddate : This shows the date when the file was last modified in local system.