Running on your device · 0 bytes uploaded

Fonts, codecs, GPU, storage, permissions

The five probes that need real work — text measurement for fonts, a real WebGL context, a real WebGPU adapter request, storage estimates, and permission queries — each with its limitations stated on the panel.
Runs only when you press the button — nothing probes, renders, or queries on loadRun the probes

Nothing runs until you press the button — font measurement, context creation, and adapter requests all happen on your click, in this tab.

- Font measurement and WebGL context creation allocate real graphics/text state; running them on every page load would be waste — and font probing without a user action is exactly the fingerprinting pattern this page discloses rather than performs.
- Every family has a browser-specific state that reads like failure but is policy: masked GPU strings, withheld debug extensions, not-queryable permission names, null adapters. The panels name each one instead of printing a red cross.
- All five families run in this tab and report only to it — the network pane stays empty for the whole run (the privacy contract every tool on this site keeps).
Nothing in yet

Paste, drop, or type to begin. Everything stays on this device.

idle — probes run on your click, never on load

Next door in Browser

- Capability dashboard (/browser/capabilities)
- Feature support (/browser/feature-support)
All browser tools (/browser)

Canonical HTML: https://nutter.tools/browser/probes
Markdown version: https://nutter.tools/browser/probes/index.md
Plain-text version: https://nutter.tools/browser/probes/index.txt
Agent index: https://nutter.tools/llms.txt