Software developers use online validation. A key found on a public forum is likely blacklisted and won't work, wasting your time.
Software like VLC (for media), LibreOffice (for documents), and 7-Zip (for archives) are completely free and open source. fileviewpro license key
Many websites allow you to upload a "mystery" file and view its contents safely in your browser without installing anything. Software developers use online validation
Want a short social-media-style version or a longer blog post on why buying legit matters? LibreOffice (for documents)