MULTI-DEVICE WIRELESS KEYBOARD K780

Overview

The Logitech Multi-Device Wireless Keyboard K780 is a full-size wireless keyboard that pairs with up to three devices and switches between them with a single key press. The honest framing: this is not a tool for typing faster, it is a tool for spending less time moving between screens.

It has a 78-key layout with a numeric keypad, dual connectivity via Bluetooth 4.0 LE and the Logitech Unifying receiver, and a rechargeable battery rated for up to two years per full charge.

On Amazon.co.jp it carries a 4.6 out of 5 rating from 3,167 reviews.

It earns its keep when a work laptop, a personal desktop, and a tablet all share one desk. If you only ever face a single PC, the same budget buys a far better typing experience elsewhere.

Compatibility Guide

Supported platforms are Windows, macOS, Chrome OS, Android, iOS, and iPadOS, over either Bluetooth 4.0 LE or the bundled Unifying receiver.

That dual setup matters in practice: use the receiver for a desktop with no Bluetooth radio, or for machines where a Bluetooth keyboard is dead in the BIOS/UEFI screen, and use Bluetooth for laptops and tablets. The usual arrangement is to assign the receiver to the one device that must never drop, and Bluetooth to the other two.

Physically it measures 380×158×22 mm and weighs 875g including batteries. Check those numbers against your desk before buying.

The 158mm depth is unusually deep for a full-size board because the top edge houses a rubber cradle that holds a phone or tablet upright. On a desk shallower than about 60cm, the keyboard plus a mouse pad plus a monitor stand gets tight.

The 875g mass is a virtue for a stationary board — it does not slide — and a clear drawback if you planned to carry it.

Per-OS key differences are handled by dual-legend keycaps: the same keys read as command/option on a Mac and as the Windows key on a PC. If you use a Japanese layout, the kana/alphanumeric toggle depends on the OS keyboard settings, so verify that mapping once after pairing.

Product Info

The headline number is the two-year battery, but that is a manufacturer figure for a full charge and will vary with how hard you use it. Still, the practical effect is real: you stop thinking about charging for months at a time.

The micro USB charging port, on the other hand, shows the product's 2016 origins — if your cables are all USB-C, you will need to keep one legacy cable around.

Pricing on Amazon JP was ￥15,150 as captured on 31 August 2026. Prices move often with stock and sales, so check the product page for the current figure.

That is not cheap for a single-function wireless keyboard. What you are paying for is three-device switching, multi-month battery, and durability — not typing feel.

Framing it that way keeps expectations aligned after purchase.

The 4.6-star average across 3,167 reviews is notable for a product this old.

A simple mechanism with few failure points is the most likely explanation.

How It Compares

Within Logitech's own range there are thinner, lighter travel boards and mechanical models sold on feel. The K780 sits at a specific intersection — full size with a numpad and multi-device switching — and surprisingly few products still occupy it.

Drop the numpad requirement and your options multiply, with thinner, lighter, cheaper choices available.

Against mechanical keyboards the priorities invert. Mechanical buys you feel and customization; the K780 buys you silence and switching speed.

The round keycaps make finger placement consistent and reduce mistypes, but the shallow travel means less typing sensation. Try one in a store if you can.

What Trips People Up

Switching is not instantaneous. Expect roughly a second or two between pressing the button and the new device responding.

A few switches per hour is fine; bouncing between two machines every minute makes that delay add up.

Also, the keyboard remembers three devices but your mouse does not. Unless you pair it with a Logitech Flow-capable or similarly multi-device mouse, you will end up with the keyboard on one machine and the pointer still on another.

Multi-device workflows only work when keyboard and mouse are planned together.

Best Use Cases

• People juggling a PC, a phone, and a tablet at one desk — this is the product's entire reason to exist. One keyboard replaces three, and the top cradle holds your phone so you stop reaching for it.
• Heavy number entry — accounting, bookkeeping, data entry — a numpad combined with multi-device switching is a narrow category, and this is one of the few options in it.
• Quiet environments — shallow travel keeps noise down for shared offices, late-night work, or note-taking in meetings.
• Anyone tired of battery management — a battery rated for up to two years effectively removes that chore.

Things to Check Before Buying

Not for gaming. This is a power-efficient wireless office keyboard, not a low-latency board with guaranteed n-key rollover.

For FPS, fighting, or rhythm games, buy wired or a gaming-focused wireless model instead.

Not for carrying. 875g and 380mm wide is not a daily commute keyboard.

Stationary use with occasional room-to-room moves is the realistic ceiling.

Do not expect mechanical feel. Coming from a mechanical board, the shallow travel will likely disappoint.

Coming from a laptop keyboard, the transition is seamless.

Micro USB charging. If you have standardized on USB-C, this one device forces an old cable to stay on your desk.

Low frequency, but a real annoyance.

The multi-device benefit evaporates below three devices. With only two machines to switch between, the price premium is harder to justify.

The third device is the tipping point.

Watch the listing details. This item may be sold by a marketplace seller rather than shipped by the manufacturer, and warranty terms can differ between parallel imports and domestic retail stock.

Confirm the seller and warranty before ordering. Listing metadata — model numbers, bundled items, keyboard layout — is also occasionally wrong, so use the product images and title to confirm whether you are getting a Japanese or US layout.

FAQ

Q. Does the battery really last two years? A.

Up to two years is a manufacturer figure for a full charge and varies with usage. Treat it as "forget about it for months," not as a guarantee.

Q. Bluetooth or the Unifying receiver? A.

Give the receiver to the device that must always work — especially a desktop where you need BIOS/UEFI access — and use Bluetooth for laptops and tablets. You can mix both up to three devices total.

Q. Can I type Japanese on an iPad or Android phone? A.

Yes, using the OS input method. The kana/alphanumeric toggle mapping depends on OS keyboard settings, so check it once after pairing.

Q. Can I charge my phone while it sits in the cradle? A.

Depending on the phone and case, the charging port may sit against the cradle. With a thick case, remove it and test the fit first.

Q. How quiet is it? A.

Clearly quieter than a mechanical keyboard thanks to the shallow travel, but not silent. Do not expect total silence.

Q. Can I use it as a wired keyboard? A.

The bundled USB cable is for charging. You can keep working wirelessly while it charges, so this is rarely a limitation, but it is not a wired keyboard.

Product Disclosure (Amazon)

• Manufacturer: Logitech
• Seller: グリーンマイルズウェイ
• Fulfilled by: グリーンマイルズウェイ
• ASIN: B01LZTBKBG
• Note: This article covers a manufacturer-made product based on Amazon listing details.