How to make a bootable linux installation usb on mac?

When creating bootable Linux USB on Mac, your primary hurdle is Apple's T2 Security Chip or Apple Silicon (M1/M2/M3/M4). For Intel Macs with the T2 chip, you must boot into Recovery Mode and use the Startup Security Utility to Allow booting from external media. On newer Apple Silicon Macs, the process is different; you’ll often need to use specific ARM-based ISOs, as standard x86 Linux images won't run natively.

Format your USB drive using GUID Partition Map rather than MBR if you are preparing it manually. Macs use EFI  to boot, and they are much more likely to recognize an external drive that follows the GPT standard. Most modern flashing tools do this automatically, but if you're using a manual tool, selecting "GPT" ensures the Mac's boot manager sees the drive when you hold the Option (Alt) key during startup.

Finally, prioritize Linux distributions with strong kernel support for Mac hardware, such as Fedora or Ubuntu. Macs have proprietary drivers for Wi-Fi cards, webcams, and trackpads that many standard Linux kernels don't include out of the box. Using a "Live" environment first allows you to verify that your keyboard and internet connection actually work before you commit to a full installation.