If an object cannot be previewed but is downloaded when you use a browser to access the object, you can refer to this topic to check your Object Storage Service (OSS), Alibaba Cloud CDN (CDN), and browser settings to troubleshoot the issue.
Item | Cause | Solution |
OSS | You used the default domain name or an OSS-accelerated endpoint to access the object. To ensure data transmission security, 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: | Use a custom domain name to access the object. Before you use a custom domain name, you must map the domain name to the bucket. For more information, see Map a custom domain name to the default domain name of a bucket. |
The value of the | Modify the value of the Content-Type header based on the object type. For more information, see How do I configure the Content-Type header? | |
The | Set the Content-Disposition header to | |
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. For example, your browser may not support preview of XLS, DOC, PPT, or PDF files. | Install a plug-in for your browser to support preview for specific file formats. |
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
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) | At or after 08:00 on September 28, 2018 | Buckets created in a specific region | text/html | |
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) | At or after 12:00:00 on September 25, 2019 | |||
China (Hong Kong) | At or after 14:00:00 on November 25, 2019 | |||
China (Hohhot) | At or after 17:00:00 on September 23, 2019 |
| ||
China (Qingdao) and China (Chengdu) | At or after 11:00:00 on September 24, 2019 | |||
China (Zhangjiakou) | At or after 17:00:00 on September 24, 2019 | |||
China (Shanghai) and China (Shenzhen) | At or after 17:00:00 on September 29, 2019 | |||
China (Beijing) | At or after 18:00:00 on September 29, 2019 | |||
China (Hangzhou) and China (Ulanqab) | At or after 15:00:00 on September 30, 2019 | |||
At or after 00:00:00 on October 09, 2022 | Users who have activated OSS |
Acceleration endpoints
Effective region | Effective at | Applicable scope | Content-Type | x-oss-ec |
At or after 00:00:00 on December 31, 2020 | Bucket for which transfer acceleration is enabled in the specified regions | text/html | ||
UAE (Dubai) | At or after 12:00:00 on January 07, 2021 | |||
Malaysia (Kuala Lumpur), and UK (London) | At or after 18:00:00 on January 07, 2021 | |||
Japan (Tokyo), Indonesia (Jakarta), and Germany (Frankfurt) | At or after 18:00:00 on January 8, 2021 | |||
US (Silicon Valley), US (Virginia), and Singapore | At or after 12:00:00 on January 14, 2021 | |||
China (Hong Kong) | At or after 00:00:00 on January 16, 2021 | |||
South Korea (Seoul), Philippines (Manila), and Thailand (Bangkok) | At or after 00:00:00 on February 01, 2023 |