Output
Temporary-file write and read throughput
UserBenchmark / All Tools / Drive Speed Test
Performance
Drive Speed Test
Write and read a temporary test file in a folder you explicitly select. Requires the File System Access API.
Free to useNo downloadNo sign-up
Drive Speed Test · At a glance
Quick answer: Write and read a temporary test file in a folder you explicitly select. Requires the File System Access API. The test uses a bounded temporary file, so caches and connection mode can dominate.
Drive Speed Test
The test loads when you open it. Device access is requested only after you choose to start.
Detailed guide
How to use this tool
- Choose a folder on the intended drive and start the explicit read/write operation.
- Leave the drive connected until cleanup completes.
Input
Explicitly selected folder; 16 MiB test file
Browser requirement
HTTPS; File System Access API
Processing
Runs on your device; no tool-result upload
How it works and what the result means
A uniquely named temporary file is written, read and removed. Operating-system caching and USB connection mode can strongly affect measured speed.
Reading the result
The test uses a bounded temporary file, so caches and connection mode can dominate. It does not scan the entire device for faults.
What to check next
Use a supported Chromium browser with directory access and enough free space. Check that you selected the external drive rather than a local folder.
Only supported Chromium-based browsers expose the required directory picker. Pick a folder with free space; do not disconnect the drive during a test.
Frequently asked questions
Will the test overwrite my existing files?
It uses a uniquely named temporary test file and removes that file afterward. It does not intentionally overwrite existing files in the selected folder.
How do I start the Drive Speed Test?
Choose a folder on the drive you want to test, then explicitly start the read/write test. The browser asks for folder access.
Does this tool require a download or an account?
No. Open the interactive tool above in a modern browser. The instructions and explanations are available even with JavaScript disabled; running a test needs JavaScript.
Why can two attempts give different results?
Power settings, background tasks, browser scheduling, operating-system input processing and device settings affect measurements. Compare repeated attempts with identical settings rather than the single highest score.