Install on Mac

For macOS 11 (Big Sur) and later, on Apple Silicon and Intel.

isotunnel is distributed straight from this site rather than the App Store. Because it isn't signed with a paid Apple certificate yet, macOS blocks it the first time and needs one extra step. That step is included for you — here's the whole thing.

1. Open the downloaded isotunnel.dmg, then drag isotunnel onto the Applications folder shown beside it.
2. In the same window, double-click Open isotunnel.command. A small Terminal window opens, prepares isotunnel, and launches it. If macOS warns about a file from the internet, choose Open. You normally only do this once.
3. isotunnel opens. Paste your access key and sign in.

Why the extra step?

Apple blocks apps that aren't signed and notarised through its US$99/year developer program. Until isotunnel joins that program, the opener does the two things notarisation would otherwise make unnecessary: it removes the "downloaded from the internet" quarantine flag and signs the app locally on your Mac. It only ever touches isotunnel, and it changes no system-wide security setting — it's the Mac version of clicking "Run anyway" on Windows.

Prefer the Terminal?

Instead of the opener, you can run this after dragging isotunnel to Applications:

xattr -dr com.apple.quarantine /Applications/isotunnel.app && \
codesign --force --deep --sign - /Applications/isotunnel.app

If it still won't open

Make sure isotunnel is in your Applications folder, then run the opener (or the Terminal command) again. After a macOS update you may need to run it once more. Still stuck? Get in touch and include your macOS version.