HTMLImageElement.lowSrc

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用法注意事项
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过时
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

非标
此特征是非标准的，且不在标准轨道中。不要在面向 Web 的生产站点中使用它：它不适用于每个用户。实现之间可能存在大的不兼容性，且行为将来可能改变。

HTMLImageElement 接口的 obsolete lowSrc property can be used to specify the URL of a reduced-quality or otherwise faster-loading version of the image specified by the src 特性。

This property reflects the HTML lowsrc 属性。

句法

htmlImageElement.lowSrc = imageUrl;
imageUrl = htmlImageElement.lowSrc;

值

A DOMString specifying the URL of a version of the image specified by src which has been modified in some fashion so that it loads significantly more quickly than the primary image.

There are a number of ways to achieve this; primary among them:

Higher compression levels (for example, a primary image saved as a JPEG using 85% quality might have a lowSrc version saved at 15%.
Reduced color depth; a primary image in 32-bit color might have an alternate image in 8-bit color.

重要： lowSrc property is obsolete and should not be used. Instead, you should use an image format which loads progressively (such as progressive JPEG). Or simply make sure your images are all well-optimized and balanced for appearance versus size.

用法注意事项

lowSrc is a strange case. It was never technically part of the HTML specification (it was a Mozilla extension to HTML); however, HTML 5 does list it among the obsolete attributes.

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`lowSrc`	Chrome 1	Edge ≤18	Firefox Yes	IE ?	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android ?	Opera Android ?	Safari iOS ?	Samsung Internet Android Yes

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完整支持
兼容性未知 ?

元数据

最后修改： Dec 8, 2019

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值

用法注意事项

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图例

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