Web Serial Test

Check whether the browser exposes the Web Serial API.

🔒 Local-first◉ Modern browser recommended.

⌁

Web Serial TestConnectivity & Hardware APIs

Local-first

Ready

Hardware connections dashboard

API → Permission → Device → Connection → Data. Availability and permission are not evidence of hardware health. Access starts only after your action.

API	API supported	HTTPS	Permission	Requires gesture	Selected device	Connection	Data received	Final status

Unsupported · Prompt · Granted · Denied · HTTPS required · User action required · Policy blocked · No device

Selected test

Exposed by browser—

Secure context—

Selected device—

RX is read-only by default. Opening a port may reset some boards through browser or driver signals. Use known equipment.

BaudData bitsStop bitsParityFlow controlRX display

Advanced

Sending bytes or changing DTR/RTS/BREAK can reset, reconfigure or damage an unknown device. Enable only when you know its protocol.

Enable manual TX for this connection

TX formatTX payload (maximum 256 bytes)

Enable manual signal changes for this connection

DTR RTS BREAK

Loopback: only on a known TTL UART adapter, connect its TX to RX with matching voltage and a shared reference as specified by its manual. Never short power pins or RS-232/RS-485 lines. A manual test payload requires explicit TX enable.

Browser-observed RX/event rates are not USB polling rate or latency. Preview is bounded; total counters include all received bytes/events.

Browser-reported details

Logs may contain sensitive device data. Export is local and explicit; no upload or automatic persistence. Summary omits product names, device IDs and report bytes. Stop or hide this page to release connections.

How it works

Use the interactive panel above and watch the live measurements. Results depend on events and capabilities exposed by your browser.

Runs in your browser

Core tests are processed locally in your browser. Camera and microphone streams are not intentionally uploaded by Testvexa.

FAQ

Does this test upload my input?

Core interaction is processed in your browser. Testvexa does not intentionally upload camera or microphone streams.

Can browser limitations affect the result?

Yes. Browsers expose different hardware APIs, so unsupported access is not the same as faulty hardware.