Our verdict: OCCT is one of the most complete free tools for checking whether an overclocked or new PC is really stable. It tests CPU, GPU, memory and power delivery while showing detailed sensor readings. The free Personal edition limits test duration, adds a wait between tests and may only be used privately.
About OCCT
OCCT is a stability testing tool from OCBASE. Its tests load the CPU, GPU, system memory and video memory, and a power test loads CPU and GPU together to stress the power supply. Errors are detected and reported, which is the point: a PC that only crashes under rare loads can be caught before it corrupts data. OCCT is a portable executable with no installation and no external dependencies.
Monitoring and system information come from HWiNFO, with tables and real-time graphs of temperatures, clocks, voltages and power. Benchmarks for CPU and memory, including a memory latency and bandwidth test, can be compared online. The Personal edition is free for personal use only; the paid Supporter edition removes the test duration limit and wait time and adds test reports and stability certificates, and businesses need a Pro or Enterprise license.
What it does well
- Stability tests. CPU, GPU 3D, memory, VRAM and combined power supply tests with error detection.
- Sensor monitoring. HWiNFO-based readings with tables and real-time graphs.
- Benchmarks. CPU and memory latency and bandwidth benchmarks with online comparison.
- System information. Detailed hardware properties, including memory timings.
- Portable. A single executable that runs without installation.
Who it is for
Good fit
Overclockers, PC builders and gamers checking a new or tuned system for stability.
Look elsewhere
Repair shops and businesses, which need a paid license, and anyone who wants long unattended free test runs.
Pros and cons
Pros
- Covers CPU, GPU, RAM, VRAM and PSU in one tool
- Detailed HWiNFO sensor data
- Portable, no installation
- Clear error reporting
Cons
- Free edition limits test duration and adds wait time between tests
- Test reports and certificates require a paid edition
- Free edition is not allowed for commercial use
How to install OCCT
Open the official download page, tick the box confirming personal use and download the Windows build. OCCT is a single portable file; run it as administrator so it can read all sensors. Watch temperatures during the first tests and stop if they climb too high.
Questions about OCCT
Is OCCT free?
The Personal edition is free for personal, non-commercial use. It has limited test duration and a wait between tests; paid editions remove those limits.
Can I use OCCT at work?
Not the free edition. OCBASE requires a Pro, Enterprise or Enterprise+ license in any commercial or business environment.
