Question

When you use a <input type="file"> in your application you get the file select dialog box with all files as default.

Is there a way to specify file types for that? Is it possible for example to select “.txt” files only?

Answer 1

This is really simple. All you do is add an accept attribute that defines what file extensions you’d like to allow.

<input type="file" accept="image/gif,image/jpeg">

That input would allow only gif and jpegs, but you can allow any comma separated list.

See:
http://www.cs.tut.fi/~jkorpela/forms/file.html#filter
http://www.w3schools.com/tags/att_input_accept.asp

edit: sure, you can do this with javascript too, by checking the filetype after selecting a file, but wouldn’t you rather check before the user selects a file?