Web Serial is not supported in this browser
Short answer: browser flashing needs the Web Serial API, and not every browser has it. Use desktop Chrome or Edge for a flow that always works. Safari and iPhone/iPad never support it; Firefox only got it in version 151 for desktop (May 2026), and Firefox on Android still doesn't.
Which browsers can flash
| Browser | Web Serial | Notes |
|---|---|---|
| Chrome / Edge (desktop) | ✅ Yes | Since v89 — the recommended, always-tested path. |
| Opera (desktop) | ✅ Yes | Since v76. |
| Chrome (Android) | ✅ Yes | Shipped in Chrome 148 (2026). |
| Firefox (desktop) | ⚠️ 151+ only | Enabled by default from Firefox 151 (2026-05-21); older versions — and enterprise-locked profiles — don't. |
| Firefox (Android) | ❌ No | Not supported. |
| Safari (macOS) | ❌ No | Apple/WebKit opposes the API over fingerprinting concerns. |
| Any browser on iPhone / iPad | ❌ No | All iOS/iPadOS browsers use WebKit, so none can flash. |
For the smoothest experience — and because it's what this flasher is built and tested on — use desktop Chrome or Edge.
Why iPhone and iPad can't flash
Every browser on iOS and iPadOS (including the App Store "Chrome" and "Firefox") is required to use Apple's WebKit engine, which doesn't implement Web Serial. So no iOS browser can flash — you need a desktop or laptop.
Two other requirements
Even in a supported browser, Web Serial only works when:
- the page is served over HTTPS (or
localhost) — a secure context; and - you start from a click or tap — the browser only shows the serial-port picker in response to a user gesture.
flash.pingequa.com runs over HTTPS, so you just click Connect and pick the port.
Sources
- MDN — Web Serial API (secure-context and user-gesture requirements; "not Baseline because it does not work in some of the most widely-used browsers").
- Can I use — Web Serial (Chrome/Edge/Opera support; Safari and Firefox status).
- Mozilla Hacks — "Web Serial support in Firefox" (2026-05-21: Firefox 151 desktop, enabled by default).
Checked 2026-07.