HEAD Object

Overview
This API is used to determine whether an object exists and whether you have permission to access it. You can use this API to get the object metadata if you can access it. To call this API, you need to have permission to read the object, or the object is set to public-read (i.e., everyone can read it).
﻿
Authorization Description
In the authorization policy, set action to cos:HeadObject. View all actions.
Versioning
With versioning enabled, you can specify the versionId request parameter to get the metadata of an object of a specified version. If the version ID you specify corresponds to a delete marker, HTTP status code “404 (Not Found)” will be returned. If no version ID is specified, the metadata of the latest version will be returned.
Request
Sample request
HEAD /<ObjectKey> HTTP/1.1
Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
Date: GMT Date
Authorization: Auth String
Note: 
Host:<BucketName-APPID>.cos.<Region>.myqcloud.com, where <BucketName-APPID> is the is the bucket name followed by the APPID, such as examplebucket-1250000000 (see Bucket Overview > Basic Information and Bucket Overview > Bucket Naming Conventions), and <Region> is a COS region (see Regions and Access Endpoints).
Authorization: Auth String (See Request Signature for details.)
Request parameters
Parameter
Description
Type
Required
versionId
Specifies the version ID of the object if versioning is enabled; if this parameter is not specified, the latest version will be queried
string
No
Request headers
In addition to common request headers, this API also supports the following request headers. For more information about common request headers, please see Common Request Headers.
Header
Description
Type
Required
If-Modified-Since
If the object is modified after the specified time, HTTP status code 200 (OK) will be returned. Otherwise, “304 (Not Modified)” will be returned.
string
No
If-Unmodified-Since
If the object is not modified after the specified time, HTTP status code 200 (OK) will be returned. Otherwise, “412 (Precondition Failed)” will be returned.
string
No
If-Match
If the ETag of the object is the same as the specified value, HTTP status code 200 (OK) will be returned. Otherwise, “412 (Precondition Failed)” will be returned.
string
No
If-None-Match
If the ETag of the object is different from the specified value, HTTP status code 200 (OK) will be returned. Otherwise, “304 (Not Modified)” will be returned.
string
No
Server-side encryption headers
If server-side encryption is used for the specified object and the encryption method is SSE-C, you will need to specify the headers related to server-side encryption to decrypt the object. For more information, see Server-side Encryption Headers.
Request body
This API does not have a request body.
Response
Response headers
In addition to common response headers, this API also returns the following response headers. For more information about common response headers, please see Common Response Headers.
Header
Description
Type
Cache-Control
Cache directives as defined in RFC 2616, which will be returned only if it is contained in the object metadata
string
Content-Disposition
Filename as defined in RFC 2616, which will be returned only if it is contained in the object metadata
String
Content-Encoding
Encoding format as defined in RFC 2616, which will be returned only if it is contained in the object metadata
string
Expires
Cache expiration time as defined in RFC 2616, which will be returned only if it is contained in the object metadata
string
x-cos-meta-*
Contains user-defined metadata and header suffixes
string
x-cos-storage-class
Object storage class. For the enumerated values, such as INTELLIGENT_TIERING, STANDARD_IA, ARCHIVE, and DEEP_ARCHIVE, please see Storage Class Overview. Note that this header will be returned only if the object’s storage class is not STANDARD.
enum
x-cos-storage-tier
Specifies the access tier of INTELLIGENT TIERING objects. Valid values:
FREQUENT
INFREQUENT
ARCHIVE_ACCESS
DEEP_ARCHIVE_ACCESS
enum
Archived object−related headers
If the storage class of the object is ARCHIVE and POST Object restore has been called to restore it, the following response headers will be returned:
Header
Description
Type
x-cos-restore
Indicates the status of the restoration process:
If the restoration is ongoing, the value of the response header will be ongoing-request="true"
If the object has already been restored, the response header will include the time when COS will delete the temporary copy, e.g., ongoing-request="false", expiry-date="Tue, 19 Nov 2019 16:00:00 GMT"
string
x-cos-restore-status
This response header will be returned if the restoration is ongoing, indicating the current restoration mode, the request time of the restoration and the expected completion time of restoration.    tier="standard"; request-date="Mon, 18 Nov 2019 09:34:50 GMT";expect-restore-date="Fri, 27 Dec 2019 08:20:00 GMT"For more information on restoration modes, see POST Object restore              
Note:
Only archive-type objects support displaying the expected completion time of restoration. Deep archive objects do not support displaying the expected completion time of restoration.
﻿
string
Versioning-related headers
If the target object is from a versioning-enabled bucket, the following response header will be returned:
Header
Description
Type
x-cos-version-id
Object version ID
string
Server-side encryption headers
If server-side encryption is used for the specified object, this API will return the server-side encryption headers. For more information, see Server-side Encryption Headers.
Bucket replication-related headers
If the object is the source or target object of bucket replication, the following response headers will be returned.
Name
Description
Type
x-cos-replication-status
Current replication status. The source object shows Pending, Failed, or Complete. The target object shows Replica.
string
Response body
The response body of this API is empty.
Error codes
This API returns common error responses and error codes. For more information, please see Error Codes.
Examples
Example 1: simple use case (with versioning disabled)
Request
HEAD /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Fri, 10 Apr 2020 18:17:36 GMT
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542656;1586549856&q-key-time=1586542656;1586549856&q-header-list=date;host&q-url-param-list=&q-signature=cde88925e00d1c90ba74985ca43b610bdf6b****
Connection: close
Response
HTTP/1.1 200 OK
Content-Type: image/jpeg
Content-Length: 16
Connection: close
Date: Fri, 10 Apr 2020 18:17:36 GMT
ETag: "ee8de918d05640145b18f70f4c3aa602"
Last-Modified: Fri, 10 Apr 2020 18:17:25 GMT
Server: tencent-cos
x-cos-hash-crc64ecma: 16749565679157681890
x-cos-request-id: NWU5MGI4NDBfNjFjODJhMDlfMzY2NjVfMjNi****
Example 2: specifying search criteria through the request headers with HTTP status code 304 (Not Modified) returned
Request
HEAD /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Wed, 29 Jul 2020 06:51:49 GMT
If-None-Match: "ee8de918d05640145b18f70f4c3aa602"
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1596005509;1596012709&q-key-time=1596005509;1596012709&q-header-list=date;host;if-none-match&q-url-param-list=&q-signature=9d087f05c259ca271efe91fc780cdced75c6****
Connection: close
Response
HTTP/1.1 304 Not Modified
Content-Type: application/xml
Content-Length: 0
Connection: close
Date: Wed, 29 Jul 2020 06:51:49 GMT
Server: tencent-cos
x-cos-request-id: NWYyMTFjODVfZDNjODJhMDlfMWU1MWVfOTUy****
x-cos-trace-id: OGVmYzZiMmQzYjA2OWNhODk0NTRkMTBiOWVmMDAxODczNTBmNjMwZmQ0MTZkMjg0NjlkNTYyNmY4ZTRkZTk0NzJmZTI0ZmJhYTZmZjYyNmU5ZGNlZDI5YjkyODkwYjNhZjhlNGQ0MDY1ZGIxNDEwMWYwOTg1NDc4Mzg4MTE3****
Example 3: specifying search criteria through the request header with HTTP status code 412 (Precondition Failed) returned
Request
HEAD /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Wed, 29 Jul 2020 06:51:50 GMT
If-Match: "aa488bb80185a6be87f4a7b936a80752"
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1596005510;1596012710&q-key-time=1596005510;1596012710&q-header-list=date;host;if-match&q-url-param-list=&q-signature=38afe94fc61ca0b3aa763e00b23fd90ac23e****
Connection: close
Response
HTTP/1.1 412 Precondition Failed
Content-Type: application/xml
Content-Length: 0
Connection: close
Date: Wed, 29 Jul 2020 06:51:50 GMT
Server: tencent-cos
x-cos-request-id: NWYyMTFjODZfMzBjMDJhMDlfMmU3ZF9kYTE4****
x-cos-trace-id: OGVmYzZiMmQzYjA2OWNhODk0NTRkMTBiOWVmMDAxODczNTBmNjMwZmQ0MTZkMjg0NjlkNTYyNmY4ZTRkZTk0NzJmZTI0ZmJhYTZmZjYyNmU5ZGNlZDI5YjkyODkwYjNhZDRkOWFlZjczOWExNjZmY2RiNjhjNGIwZWQ3YjYw****
Example 4: using server-side encryption SSE-COS
Request
HEAD /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Fri, 10 Apr 2020 18:18:19 GMT
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542699;1586549899&q-key-time=1586542699;1586549899&q-header-list=date;host&q-url-param-list=&q-signature=6a6d4dd5b5a9e6379f300715985bfb60b947****
Connection: close
Response
HTTP/1.1 200 OK
Content-Type: image/jpeg
Content-Length: 16
Connection: close
Date: Fri, 10 Apr 2020 18:18:19 GMT
ETag: "ee8de918d05640145b18f70f4c3aa602"
Last-Modified: Fri, 10 Apr 2020 18:18:08 GMT
Server: tencent-cos
x-cos-hash-crc64ecma: 16749565679157681890
x-cos-request-id: NWU5MGI4NmJfNmRjMDJhMDlfZGQwNl8xZmE4****
x-cos-server-side-encryption: AES256
Example 5: using server-side encryption SSE-KMS
Request
HEAD /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Fri, 10 Apr 2020 18:18:30 GMT
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542710;1586549910&q-key-time=1586542710;1586549910&q-header-list=date;host&q-url-param-list=&q-signature=7c8a1c93b9701e653c2ab00419f976397d00****
Connection: close
Response
HTTP/1.1 200 OK
Content-Type: image/jpeg
Content-Length: 16
Connection: close
Date: Fri, 10 Apr 2020 18:18:30 GMT
ETag: "00ca268468481b847fc2d8a9bd84578d"
Last-Modified: Fri, 10 Apr 2020 18:18:19 GMT
Server: tencent-cos
x-cos-hash-crc64ecma: 16749565679157681890
x-cos-request-id: NWU5MGI4NzZfN2FjODJhMDlfMjU3N18xYTEz****
x-cos-server-side-encryption: cos/kms
x-cos-server-side-encryption-cos-kms-key-id: 48ba38aa-26c5-11ea-855c-52540085****
﻿
Example 6: using server-side encryption SSE-C
Request
HEAD /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Fri, 10 Apr 2020 18:18:41 GMT
x-cos-server-side-encryption-customer-algorithm: AES256
x-cos-server-side-encryption-customer-key: MDEyMzQ1Njc4OUFCQ0RFRjAxMjM0NTY3ODlBQkNE****
x-cos-server-side-encryption-customer-key-MD5: U5L61r7jcwdNvT7frmUG****
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542721;1586549921&q-key-time=1586542721;1586549921&q-header-list=date;host;x-cos-server-side-encryption-customer-algorithm;x-cos-server-side-encryption-customer-key;x-cos-server-side-encryption-customer-key-md5&q-url-param-list=&q-signature=99ad258fc295f43feb0546bb2346c8269dc5****
Connection: close
Response
HTTP/1.1 200 OK
Content-Type: image/jpeg
Content-Length: 16
Connection: close
Date: Fri, 10 Apr 2020 18:18:41 GMT
ETag: "582d9105f71525f3c161984bc005efb5"
Last-Modified: Fri, 10 Apr 2020 18:18:31 GMT
Server: tencent-cos
x-cos-hash-crc64ecma: 16749565679157681890
x-cos-request-id: NWU5MGI4ODFfN2NiODJhMDlfMmFmYTVfMWRh****
x-cos-server-side-encryption-customer-algorithm: AES256
x-cos-server-side-encryption-customer-key-MD5: U5L61r7jcwdNvT7frmUG****
Example 7: requesting the latest version of an object (with versioning enabled)
Request
HEAD /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Fri, 10 Apr 2020 18:19:15 GMT
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542755;1586549955&q-key-time=1586542755;1586549955&q-header-list=date;host&q-url-param-list=&q-signature=7909dc19780873dfaa51c8b238254098ca1a****
Connection: close
Response
HTTP/1.1 200 OK
Content-Type: image/jpeg
Content-Length: 26
Connection: close
Date: Fri, 10 Apr 2020 18:19:15 GMT
ETag: "22e024392de860289f0baa7d6cf8a549"
Last-Modified: Fri, 10 Apr 2020 18:19:04 GMT
Server: tencent-cos
x-cos-hash-crc64ecma: 11596229263574363878
x-cos-request-id: NWU5MGI4YTNfZDZjODJhMDlfYmU0MV8xM2Y5****
x-cos-version-id: MTg0NDUxNTc1MzA5NjQ2ODI5MTg
Example 8: requesting a specific version of an object (with versioning enabled)
Request
HEAD /exampleobject?versionId=MTg0NDUxNTc1MzA5NzU4ODg1Mjg HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Fri, 10 Apr 2020 18:19:04 GMT
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542744;1586549944&q-key-time=1586542744;1586549944&q-header-list=date;host&q-url-param-list=versionid&q-signature=1307acd3e8649087c738ecca452a54fa5a79****
Connection: close
Response
HTTP/1.1 200 OK
Content-Type: image/jpeg
Content-Length: 16
Connection: close
Date: Fri, 10 Apr 2020 18:19:04 GMT
ETag: "ee8de918d05640145b18f70f4c3aa602"
Last-Modified: Fri, 10 Apr 2020 18:18:53 GMT
Server: tencent-cos
x-cos-hash-crc64ecma: 16749565679157681890
x-cos-request-id: NWU5MGI4OThfN2RiNDBiMDlfMTk1MTBfMWZj****
x-cos-version-id: MTg0NDUxNTc1MzA5NzU4ODg1Mjg
Example 9: requesting an archived object that is being restored
Request
HEAD /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Fri, 27 Dec 2019 08:19:35 GMT
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1577434775;1577441975&q-key-time=1577434775;1577441975&q-header-list=date;host&q-url-param-list=&q-signature=72408a09a5fc00d77d389559a0cfa5c98e31****
Connection: close
Response
HTTP/1.1 200 OK
Content-Type: image/jpeg
Content-Length: 13
Connection: close
Date: Fri, 27 Dec 2019 08:19:35 GMT
ETag: "b62e10bcab55a88240bd9c436cffdcf9"
Last-Modified: Fri, 27 Dec 2019 08:19:23 GMT
Server: tencent-cos
x-cos-request-id: NWUwNWJlOTdfN2VjODJhMDlfOGI1N18yYjYz****
x-cos-restore: ongoing-request="true"
x-cos-restore-status: tier="expedited"; request-date="Fri, 27 Dec 2019 08:19:29 GMT"
x-cos-storage-class: ARCHIVE
Example 10: requesting an archived object which has been restored
Request
HEAD /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
Date: Thu, 02 Jan 2020 18:09:51 GMT
Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1577988591;1577995791&q-key-time=1577988591;1577995791&q-header-list=date;host&q-url-param-list=&q-signature=ff23b3a44945f019916450add646e963c29b****
Connection: close
Response
HTTP/1.1 200 OK
Content-Type: image/jpeg
Content-Length: 16
Connection: close
Date: Fri, 10 Apr 2020 18:17:36 GMT
ETag: "ee8de918d05640145b18f70f4c3aa602"
Last-Modified: Fri, 10 Apr 2020 18:17:25 GMT
Server: tencent-cos
x-cos-hash-crc64ecma: 16749565679157681890
x-cos-request-id: NWU5MWRiZjFfMmViMDJhMDlfNjIwOF8zNTU0****
x-cos-restore: ongoing-request="false", expiry-date="Mon, 13 Apr 2020 16:00:00 GMT"
x-cos-storage-class: ARCHIVE
﻿

Was this page helpful?

You can also Contact Sales or Submit a Ticket for help.

Yes

Parameter	Description	Type	Required
versionId	Specifies the version ID of the object if versioning is enabled; if this parameter is not specified, the latest version will be queried	string	No

Header	Description	Type	Required
If-Modified-Since	If the object is modified after the specified time, HTTP status code 200 (OK) will be returned. Otherwise, “304 (Not Modified)” will be returned.	string	No
If-Unmodified-Since	If the object is not modified after the specified time, HTTP status code 200 (OK) will be returned. Otherwise, “412 (Precondition Failed)” will be returned.	string	No
If-Match	If the `ETag` of the object is the same as the specified value, HTTP status code 200 (OK) will be returned. Otherwise, “412 (Precondition Failed)” will be returned.	string	No
If-None-Match	If the `ETag` of the object is different from the specified value, HTTP status code 200 (OK) will be returned. Otherwise, “304 (Not Modified)” will be returned.	string	No

Name	Description	Type
x-cos-replication-status	Current replication status. The source object shows Pending, Failed, or Complete. The target object shows Replica.	string

tencent cloud

Sign Up

Log in

Compute

Microservice

Data Migration

Database SaaS Tool

Data Security

Application Security

Big Data

Image Creation

Internet of Things

Stream Services

Cloud Real-time Rendering

Management and Audit Tools

Edge Computing

Serverless

Relational Database

Networking

Business Security

Domains & Websites

Face Recognition

AI Platform Service

Middleware

Media On-Demand

Game Services

Developer Tools

Container

Essential Storage Service

Enterprise Distributed DBMS

CDN and Acceleration

Security Services

Enterprise Applications

Tencent Big Model

Natural Language Processing

Communication

Media Process Services

Education Sevices

Monitor and Operation

Distributed cloud

Data Process and Analysis

NoSQL Database

Network Security

Cloud Security

Office Collaboration

Voice Technology

Optical Character Recognition

Interactive Video Services

Media SDK

Cloud Resource Management

More

Overview

Authorization Description

Versioning

Request

Sample request

Request parameters

Request headers

Request body

Response

Response headers

Archived object−related headers

Response body

Error codes

Examples

Example 1: simple use case (with versioning disabled)

Request

Response

Example 2: specifying search criteria through the request headers with HTTP status code 304 (Not Modified) returned

Request

Response

Example 3: specifying search criteria through the request header with HTTP status code 412 (Precondition Failed) returned

Request

Response

Example 4: using server-side encryption SSE-COS

Request

Response

Example 5: using server-side encryption SSE-KMS

Request

Response