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Object Storage Service:0048-00000108

Last Updated:Mar 20, 2026

Problem description

When you use a transfer acceleration endpoint to access an OSS object from a browser, the browser shows a Save As dialog and downloads the file instead of displaying it inline.

Causes

If transfer acceleration was enabled on the bucket after 18:00:00 on January 7, 2021, OSS injects the following headers into every response served through the acceleration endpoint:

x-oss-force-download: true
Content-Disposition: attachment

Content-Disposition: attachment tells the browser to show a Save As dialog and download the file rather than render it inline.

Examples

The following example shows a GET request for an object named test in a bucket where transfer acceleration was enabled after 18:00:00 on January 7, 2021. The response includes both forced-download headers.

GET /test HTTP/1.1

HTTP/1.1 200 OK
Content-Disposition: attachment
x-oss-force-download: true

Solutions

Bind a custom domain name to the bucket and access objects through that domain. OSS does not inject forced-download headers for requests made through a custom domain, so objects are served for inline preview in the browser.

For setup instructions, see Map custom domain names.

References