Just paste the numbers into the input space and click the Deflate button. It accepts a wide variety of formats, so there's not much you need to do.
Once you've seen it Deflate, you can add filters to weed out numbers from the ones you input. For example, weed out all numbers that don't contain at least one "4". (That's a key number filter.)
All of the filters are described along with examples at the bottom of the page.