revision:
The accept attribute can only be used with <input type="file">. Tip: Do not use this attribute as a validation tool. File uploads should be validated on the server.
<input accept="file_extension | audio/* | video/* | image/* | media_type">
To specify more than one value, separate the values with a comma (e.g. <input accept="audio/*,video/*,image/*" />.
<form style="margin-left:5vw;" action="/action_page.php">
<label for="img">Select image:</label>
<input type="file" id="img" name="img" accept="image/*">
<input type="submit">
</form>
<div style="margin-left:5vw;">
<label for="soundFile">Select an audio file:</label>
<input type="file" id="soundFile" accept="audio/*">
</div>
<div style="margin-left:5vw;">
<label for="videoFile">Select a video file:</label>
<input type="file" id="videoFile" accept="video/*">
</div>
<div style="margin-left:5vw;">
<label for="imageFile">Select some images:</label>
<input type="file" id="imageFile" accept="image/*" multiple>
</div>