How to Check If Firmware Is UEFI: A Practical Guide

Name: BIOS and UEFI As Fast As Possible
Uploaded: 2026-02-18
Duration: 5 min 39 s
Description: Master the checks to confirm whether your device firmware runs in UEFI mode. This step-by-step guide covers Windows, macOS, Linux, boot-time indicators, and safe conversion options—boosting reliability and future-proofing your system.

Master the checks to confirm whether your device firmware runs in UEFI mode. This step-by-step guide covers Windows, macOS, Linux, boot-time indicators, and safe conversion options—boosting reliability and future-proofing your system.

Debricking Team

February 18, 2026·5 min read

Firmware BIOS Firmware Difference: Firmware & BIOS

Quick AnswerSteps

By the end, you’ll know how to determine if your device firmware uses UEFI, what indicators to look for, and how to safely verify or switch modes. This quick guide covers Windows, macOS, and Linux with practical checks and safeguards. According to Debricking, confirming the boot mode is essential before OS installation or troubleshooting.

What is UEFI and why check firmware mode

UEFI is the modern firmware interface that replaces the old BIOS, enabling faster boot times, better security features, and support for large disks. In this guide on how to check if firmware is uefi, you’ll learn practical checks you can perform across Windows, macOS, and Linux to verify the boot interface and prepare for changes. According to Debricking, most new devices ship with UEFI-enabled firmware, and Secure Boot is commonly enabled by default. Understanding whether your firmware runs in UEFI mode helps you plan OS installations, driver updates, and recovery strategies with confidence. If you’re troubleshooting boot issues or preparing for a fresh install, the checks below will help you identify the exact boot mode and guide you to safe next steps.

What is UEFI and why check firmware mode

Tools & Materials

A computer with admin access (Windows, macOS, or Linux)(You’ll need administrator rights to run system information tools and modify boot settings.)
Backup drive or cloud backup(Back up personal data before changing boot modes or repartitioning.)
USB recovery media (optional but recommended)(Useful if you need to reinstall the OS or repair boot-related issues.)
Stable internet connection(Helpful for downloading tools or obtaining official recovery images.)

Steps

Estimated time: 60-90 minutes

1
Back up important data
Begin with a full data backup to protect against any unintended changes. While many checks are non-destructive, evolving boot configurations can require repairs that affect data access. Ensure your backup is complete and verified before proceeding.
Tip: Verify your backup by performing a quick restore test on a non-critical file.
2
Access the firmware/BIOS setup
Restart the device and press the designated key to enter the firmware setup (usually F2, Del, or Esc). If you’re unsure, consult the on-screen prompt during boot or the device’s manual. You’re looking for a boot or security tab that mentions UEFI, Legacy, or Boot Mode.
Tip: If you can’t access the setup, try resetting the BIOS/UEFI by using the motherboard's reset button or a CMOS jumper, then retry.
3
Look for the boot mode indicator
Within the firmware interface, check for a setting named Boot Mode, Boot Priority, or BIOS Mode. If it shows UEFI or UEFI with CSM (Compatibility Support Module) enabled, you’re in UEFI mode. If it shows Legacy or BIOS, you’re in legacy mode.
Tip: Note any related options like Secure Boot; you’ll revisit these if you decide to switch modes.
4
Cross-check with OS information (Windows)
On Windows, open System Information (msinfo32) and locate BIOS Mode. If it reads UEFI, you’re in the correct mode. You can also check disk partition style by opening Disk Management and inspecting the GPT/MBR status of the boot disk.
Tip: BIOS Mode alone confirms part of the picture; GPT vs MBR helps you understand potential conversion needs.
5
Cross-check with OS information (macOS/Linux)
On macOS, System Information can indicate the Boot Mode on newer systems. On Linux, verify EFI presence by checking for /sys/firmware/efi or using efibootmgr -v. If these indicate EFI, you’re running in UEFI mode; if not, you’re likely in Legacy.
Tip: If efibootmgr isn’t installed, install the package (e.g., 'sudo apt-get install efibootmgr' on Debian-based distros).
6
Decide on switching or staying
If you discover Legacy BIOS or you need Windows 11/modern OS features, plan a safe path to switch to UEFI: backup, enable GPT, and prepare for a reinstall if needed. Converting from MBR to GPT can be done with caution using tools like MBR2GPT where supported.
Tip: Read manufacturer guidance first; some systems require a fresh install to switch reliably.
7
Make changes and validate
If you proceed with switching, ensure the boot order starts with the correct UEFI entry and verify after reboot. Confirm that you can boot into the OS and that the firmware settings reflect the new mode. Document the changes for future maintenance.
Tip: Keep a recovery USB ready in case something goes wrong during the transition.
8
Post-change verification
After the upgrade or switch, re-check BIOS/Boot Mode indicators and OS boot status. Confirm Secure Boot behavior if applicable and check that OS updates and drivers install without boot-related obstruction.
Tip: If you experience boot issues, revert to the previous boot mode and restore from backup.

Pro Tip: Always back up before changing boot modes or repartitioning.

Warning: Converting from MBR to GPT can fail and render the system unbootable if not done correctly; follow official guidance and backups.

Note: Record current boot order and firmware settings before making changes.

Pro Tip: Use a verified recovery drive and a stable power source during the process.

Questions & Answers

Is UEFI required for Windows 11?

Windows 11 generally requires UEFI with Secure Boot on most devices, especially for new installations. Some older hardware may support Windows through legacy BIOS, but this is not the typical or recommended path. Always verify your device meets the OS requirements before upgrading.

Can I switch from Legacy BIOS to UEFI without reinstalling?

In many cases you can convert a GPT disk from MBR using tools like MBR2GPT, but success depends on hardware support and current partitioning. A clean reinstall is safer for complex setups or older hardware. Always back up first.

What if I don’t see /sys/firmware/efi on Linux?

If /sys/firmware/efi does not exist, the system is likely running in Legacy BIOS mode. There are exceptions, such as nested virtualization or certain firmware configurations, but in most cases you’re not in UEFI mode.

How do I disable Secure Boot if I need to?

Secure Boot is controlled within the firmware setup or OS recovery options. To disable, enter the firmware interface, find Secure Boot, and set it to Disabled. Remember to save changes and reboot, then re-verify boot status.

Will switching to UEFI affect drives using MBR?

Switching to UEFI typically requires GPT partitioning for the boot drive. This may involve converting partitions or reinstalling the OS if conversion isn’t feasible. Back up data and consult your hardware vendor guidance.

What is the safest first step to verify boot mode?

Start with a non-destructive check from the operating system (e.g., Windows System Information, Linux /sys/firmware/efi). This helps you determine whether immediate changes are necessary before any reconfiguration.