When you publish software here you can pick more than one file: a main installer plus Additional files such as builds for other systems or a checksums file. Which one becomes the download button, and which system each file is for, is now shown before you press the button.

Where you see it

Open Create project, or Draft a new release on one of your projects. As soon as you pick files — in the Installer file or Main installer box, or in Additional files — a short list appears under the pickers, one line per file:

• mytool-2.4.0-setup.exe — Main download · Windows
• mytool-2.4.0-linux-x86_64.tar.gz — Extra file · Linux x86-64
• mytool-2.4.0.dmg — Extra file · macOS
• SHA256SUMS — Extra file · Any system

Only the file names are checked at this point. Nothing is uploaded until you press Create project or Publish release.

What the two labels mean

• Main download is the file behind the Download button on your project page.
• Extra file is listed under the release for anyone who needs it — another system's build, a checksums file, a source archive.

The system — Windows, macOS, Linux, Android or iOS, sometimes with a chip type such as x86-64 or arm64 — is read from the file name, the same way the site sorts your release files after publishing. If the name gives no clue, the file is marked Any system.

Only one file? It becomes the main download

If you leave the main box empty and pick exactly one installer or archive (for example a .exe, .dmg, .deb, .zip or .tar.gz) in Additional files, it is used as the main download — and the list says Main download next to it, so there are no surprises. It stays an Extra file when:

• you pick two or more additional files (they are treated as builds for different systems);
• the one file is not an installer or archive, such as SHA256SUMS.txt;
• on Draft a new release, you have filled in …or external download URL — then that link is the download. Type or clear the link and the list updates straight away.

Want a specific file as the download? Put it in the main box: an installer or archive there is always listed as the Main download.

Good to know

• The list uses the same rules the site uses when it saves your project, so what it says is what you get.
• It needs JavaScript. If the list does not appear, publishing still works exactly the same way — you just do not get the preview.
• A file type the site does not accept is marked Not accepted in the list — for example a .txt file in the main box — so you can swap it before anything is uploaded.

More on publishing: Publish your software in one step, Publish your first release and Check your free storage before you upload. More guides at https://jmtechpower.com/articles.