input type="file" restrict file types by pattern code example
Example 1: input limit file type html
<!-- (IE 10+, Edge (EdgeHTML), Edge (Chromium), Chrome, Firefox 42+) -->
<input type="file" accept=".jpg,.png,.pdf" />
Example 2: input type file filter extensions
<input type="file" accept=".gif,.jpg,.jpeg,.png,.doc,.docx">