MemTest86+ is a free, open-source stand-alone memory tester for x86, x86-64, ARM AArch64, and LoongArch64 computers. It runs outside the operating system, allowing it to reach almost all computer memory without operating-system memory or UEFI library restrictions. Its test algorithms, including moving inversions and Modulo-20, are intended to find memory failures that may be behind crashes, freezes, or system instability. It can start from legacy or UEFI BIOS, use Linux boot protocols, or run from a FAT32 USB drive, CD-ROM, or network boot. Testing continues indefinitely, with a pass counter advancing after each full set of selected tests. The software is free under GNU GPL version 2, with no additional restrictions on private or commercial use. Stable and nightly binaries are available, but nightly builds are automatically generated, untested, and unsupported. The binary is not signed by Microsoft, so Secure Boot must be temporarily disabled; USB device support is still a work in progress.
Who it is for
It suits users diagnosing memory-related crashes, freezes, or instability on supported systems. It is also an option for people who want a bootable memory test rather than an operating-system application.
What is good
- Free and open-source under GNU GPL version 2.
- Tests can access almost all computer memory.
- Boots from BIOS, USB, CD-ROM, or PXE.
- Includes moving inversions and Modulo-20 tests.
What to know first
- Secure Boot must be temporarily disabled.
- USB drivers do not support every device.
- Nightly builds are untested and unsupported.
Verdict
MemTest86+ offers a focused way to test system memory outside the operating system. Check Secure Boot and USB compatibility before choosing how to boot it.
MemTest86+ plans and pricing
All plansCompared on PC overclocking software
- Free plan
- Yes
- Platform support
- multi-platform
- Stress testing
- Yes
- Memory testing
- Yes
- Disk health checks
- No
- GPU testing
- No
- Bootable diagnostic media
- Yes
