I have a file upload object on my page: with the following excel files on my desktop: file1.xlsx file1.xls file.csv I want the file upload to ONLY show .xlsx, .xls, & .csv files. This string is a comma-separated list of unique file type specifiers. HTML Input="file"属性ファイルタイプ(CSV)を受け入れる (6) . Valid for the image button only, the alt attribute provides alternative text for the image, displaying the value of the attribute if the image src is missing or otherwise fails to load. I want it so that the user can input the file into the file Input field and it is placed into the source of a dynamically-created image upon button click. For example, a file picker that needs content that can be presented as an image, including both standard image formats and PDF files, might look like this: Note: You can find this example on GitHub too — see the source code, and also see it running live. When adding a file field to a form, you might want to limit the selector to images. How we can achieve this? Tip: Always add the