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Object Storage Service:What do I do if an object cannot be previewed when I access the object

Last Updated:Feb 13, 2025

If an object is forcibly downloaded when you use a browser to access the object, please check your Object Storage Service (OSS), Alibaba Cloud CDN (CDN), and browser settings to troubleshoot the issue.

Item

Cause

Solution

OSS

When you use the default domain name or an OSS-accelerated endpoint to access an object of a specific type in a bucket that is created at a specific point in time, OSS forcibly adds the following headers to the response: x-oss-force-download: true and Content-Disposition: attachment. For example, the Content-Type header of the object is text/html or image/jpeg. As a result, the object is downloaded. For more information, see Appendix: x-oss-ec rules triggered for forcible download.

Use a custom domain name to access the object and map the domain name to the bucket. For more information, see Bind a custom domain name to a bucket.

The value of the Content-Type header does not match the actual object type. In this case, the browser cannot render the object correctly and can only download the object.

Modify the value of the Content-Type header. For more information, see How do I configure the Content-Type header?

The Content-Disposition header is set to attachment, which triggers the browser to download the object instead of displaying the its content.

Set the Content-Disposition header to inline. For more information, see Manage object metadata.

CDN

Resources cached on points of presence (POPs) are not refreshed.

Refresh resources cached on POPs. For more information, see Purge and prefetch resources.

Browser

The file format is not supported for preview by your browser.

Install a plug-in for your browser.

Appendix: x-oss-ec rules triggered for forcible download

The following table describes the x-oss-ec rules that are triggered for forcible download when you use the default domain name or an acceleration endpoint of OSS to access different types of objects.

Default OSS domain name

The following table shows the times when default OSS domain names take effect and related information.

Effective region

Effective at

Applicable scope

Content-Type

x-oss-ec

China (Hangzhou), China (Shanghai), China (Qingdao), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Shenzhen), and China (Chengdu)

08:00 on September 28, 2018

Buckets created in a specific region

text/html

0048-00000001

China (Nanjing-Local Region), China (Fuzhou-Local Region), China (Wuhan-Local Region), China (Ulanqab), China (Heyuan), China (Guangzhou), US (Silicon Valley), US (Virginia), South Korea (Seoul), Singapore, Malaysia (Kuala Lumpur), Indonesia (Jakarta), Philippines (Manila), Thailand (Bangkok), UK (London), and UAE (Dubai)

12:00:00 on September 25, 2019

China (Hong Kong)

14:00:00 on November 25, 2019

China (Hohhot)

17:00:00 on September 23, 2019

  • image/jpeg

  • image/gif

  • image/tiff

  • image/png

  • image/webp

  • image/svg+xml

  • image/bmp

  • image/x-ms-bmp

  • image/x-cmu-raster

  • image/exr

  • image/x-icon

  • image/heic

  • text/html

0048-00000100

China (Qingdao) and China (Chengdu)

11:00:00 on September 24, 2019

0048-00000101

China (Zhangjiakou)

17:00:00 on September 24, 2019

0048-00000102

China (Shanghai) and China (Shenzhen)

17:00:00 on September 29, 2019

0048-00000103

China (Beijing)

18:00:00 on September 29, 2019

0048-00000104

China (Hangzhou) and China (Ulanqab)

15:00:00 on September 30, 2019

0048-00000105

All

00:00:00 on October 09, 2022

Users who have activated OSS

All

0048-00000113

Acceleration endpoints

The following table shows the times when acceleration endpoints take effect and related information.

Effective region

Effective at

Applicable scope

Content-Type

x-oss-ec

All

00:00:00 on December 31, 2020

Bucket for which transfer acceleration is enabled in the specified regions

text/html

0048-00000002

UAE (Dubai)

12:00:00 on January 07, 2021

All

0048-00000107

Malaysia (Kuala Lumpur), and UK (London)

18:00:00 on January 07, 2021

0048-00000108

Japan (Tokyo), Indonesia (Jakarta), and Germany (Frankfurt)

18:00:00 on January 8, 2021

0048-00000109

US (Silicon Valley), US (Virginia), and Singapore

12:00:00 on January 14, 2021

0048-00000101

China (Hong Kong)

00:00:00 on January 16, 2021

0048-00000111

South Korea (Seoul), Philippines (Manila), and Thailand (Bangkok)

00:00:00 on February 01, 2023

0048-00000112