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Hot Reload Across Multiple Devices

How to get instant hot reload on every device at once so a single code change updates phone, tablet, and desktop without manual refreshes.

6 min read - Updated 2026-06-15

Use this guide as a compact release reference, then validate the same breakpoints in Sizzy with synchronized devices and screenshot evidence.

The manual-refresh tax

When you test on several devices, every code change means refreshing each one - tap the phone, click the tablet window, reload desktop. That tax adds up to dozens of context switches an hour and quietly discourages thorough multi-device testing. The fix is to let your dev server's hot reload reach every device automatically.

Each manual refresh is a small context switch

The tax discourages frequent multi-device checks

Stale tabs lead to debugging code you already changed

Hot reload should fan out to every device, not just one

How HMR reaches every device

Modern dev servers like Vite, Next.js, and webpack push updates over a websocket to connected clients. Any device pointed at your dev server gets the update - the catch is keeping all those devices open and connected. A multi-device browser solves this by hosting all the viewports in one place that share the same hot-reload connection.

HMR pushes changes over a websocket to clients

Every connected viewport updates, not just the active one

Keep all devices pointed at the same dev server

Synced interaction layers on top of synced reloads

One change, every device updates

In Sizzy, all your devices live in one window connected to your dev server, so saving a file hot-reloads phone, tablet, and desktop together. Combined with synchronized scrolling and clicking, you change a media query and instantly see the result everywhere - the tightest possible responsive feedback loop.

All devices share one dev-server connection

Save once and every viewport reloads together

Pair with synced scroll and click for full coverage

Eliminate per-device manual refreshing entirely

Release checklist

All test devices point at the same dev server.

HMR is enabled and the websocket connects on each device.

A single save updates every viewport without manual refresh.

Synced interaction complements synced reloads.

Frequently asked questions

Can hot reload update multiple devices at once?

Yes. Hot module replacement pushes updates over a websocket to every connected client, so any device pointed at your dev server updates automatically. A multi-device browser keeps all viewports connected so one save refreshes them together.

Why does only one device hot reload?

Usually because the other devices aren't connected to the dev server's HMR websocket, or they're viewing a cached or different URL. Ensure every device points at the same dev-server origin and the websocket isn't blocked.

Does Sizzy support hot reload across devices?

Yes. Sizzy hosts all your devices in one window sharing the same dev-server connection, so saving a file hot-reloads phone, tablet, and desktop simultaneously, alongside synchronized scrolling and clicking.

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