Description
About Browser Storage Test
Introduction
Browser Storage Test checks origin storage the page can use: quota estimates plus local and session storage round-trips. Figures are approximate browser accounting, not a disk utility.
What this tool does
It reads storage estimate signals when available, writes and reads small localStorage and sessionStorage probes, and can run light fill or clear actions for session and local scopes. It does not report free SSD bytes.
When to use it
Use it for QuotaExceededError triage, PWA cache sizing, and private-versus-normal profile comparisons. Prefer Cookie Test for cookie behavior and Browser Features for API presence alone.
How it works
navigator.storage.estimate provides coarse usage and quota when implemented. localStorage and sessionStorage probes confirm read/write in this origin. Persistence APIs vary by engine and may be denied. Private mode often shrinks or disables storage.
Step-by-step instructions
- Open Browser Storage Test over HTTPS in the profile under test.
- Read the quota estimate or unsupported state.
- Run local and session round-trips; optionally try fill or clear actions.
- Retest in a private window if the bug only appears there.
Common problems
Quota numbers look “wrong” because browsers round or bucket them. Safari and private modes differ sharply from Chromium. Fill actions can hit quota quickly on purpose.
Privacy explanation
Probes write only diagnostic keys in this origin. DeviceHub does not upload your storage contents. Clear site data in the browser if you want probes removed.