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If you only need one keyboard and mouse to control several computers, software can replace the input-switching part of a KVM. The strongest choices depend on your operating systems, peripherals, network policy, clipboard or file-transfer needs, and whether you require open-source software. Logitech Flow is the most straightforward fit for people who already use compatible Logitech devices on Windows and macOS. Synergy is a commercial cross-platform option, while Deskflow is the open-source project identified as Synergy’s upstream. ShareMouse covers Mac and Windows, Mouse Without Borders is aimed at Windows users, and Hydra is an emerging cross-platform project.
None of these tools normally switches monitor signals. Synergy describes the distinction plainly: it works like a software KVM “but without video.” If one monitor must change between computers, you still need monitor input switching, a display switch, or a hardware KVM.
What a software KVM alternative actually does
A hardware KVM connects multiple computers to one set of peripherals and, depending on the model, one or more displays. Software alternatives handle the peripheral side: an application captures keyboard and mouse input on one computer and sends it across the local network to another. You can usually move the pointer across a screen edge or press a hotkey to change the active computer.
The Tool Desk
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#1 Best Overall
- Precision you can feel with the Haptic Sense Panel; customizable (1) haptic feedback on specific actions, shortcuts, notifications enhancing productivity on this wireless Bluetooth mouse
- Effortlessly access favorite tools with Actions Ring (2) on this MX Series mouse—a dynamic, customizable overlay adapts to each app, placing most used filters, adjustments, and shortcuts at your cursor
- Scroll 1,000 lines per second and stop on a pixel with the MagSpeed scroll wheel—Logitech’s fastest (3), quietest, and most precise (4) scrolling experience
- Enjoy 2X more powerful connectivity (7) with a USB-C dongle, advanced radio chip, and optimized antenna for faster, stronger, reliable performance—or use Bluetooth for more versatility
- Ergonomic mouse designed for comfort, MX Master 4 keeps you in flow with a natural tilt, intuitive buttons, and a thumb scroll wheel that reduces hand stress for fluid navigation
- Input sharing: keyboard and mouse control move between computers.
- Clipboard sharing: many products can copy text, and some also support images or files.
- Screen switching: usually represented by pointer movement across an edge or a configurable hotkey.
- Video switching: generally not included, so display connections must be handled separately.
Performance and reliability vary with the operating-system mix, network quality, firewall rules, and the software’s maturity. No independent comparative speed or reliability benchmark is established for these choices here, so treat vendor feature descriptions as capabilities to verify rather than as proof that one product is faster or more dependable.
Quick comparison
| Option | Computer support | Peripheral requirement | Network and transfer claims | Best fit | Important qualification |
|---|---|---|---|---|---|
| Logitech Flow | Windows and macOS, subject to device and software compatibility | Supported Logitech mouse and keyboard; the supported-device list includes the MX Master 4, but check the current list | Both computers on the same Wi-Fi or Ethernet network; copies text, images, and files | People already using compatible Logitech peripherals | Not a general-purpose solution for arbitrary keyboards and mice |
| Synergy | Cross-platform; verify support for every operating-system version in your setup | Works with existing peripherals rather than requiring one manufacturer’s hardware | Local-network sharing, clipboard features, hotkeys, screen-layout configuration, and advertised TLS/SSL encryption | Mixed-platform desks that want a commercial product | Shares input, not video; encryption claims are vendor claims, not an independent audit |
| Deskflow | Cross-platform project; current release support is version-dependent | Designed as a software route using existing peripherals | Feature set and setup depend on the current release | Readers who prefer open-source software | Confirm release maturity, operating-system support, and feature parity before relying on it daily |
| ShareMouse | Mac and Windows | Existing keyboard and mouse | Local-LAN input sharing, clipboard sharing, file drag-and-drop, and optional AES-encrypted traffic | Mac/Windows users who want transfer features | Verify the current freeware limits and license terms for personal use |
| Mouse Without Borders | Windows through PowerToys | Existing Windows peripherals | Secondary descriptions report clipboard sharing and support for multiple PCs | Windows-only desks already using PowerToys | Check Microsoft’s current installation instructions, supported Windows versions, and present limits |
| Hydra | Mac, Windows, and Linux according to its project description | Existing peripherals | Project claims include edge movement, encrypted relay connections, and file transfer | Readers willing to evaluate an emerging project | Assess release maturity, support, and whether relay networking meets your policy |
| Multiplicity | Windows option | Not stated in the available material | Search descriptions mention KVM-style switching and extra functions in higher tiers | Windows users investigating another commercial route | Current tier limits and pricing are not established; verify them before choosing |
Choose by operating system first
Windows and macOS with compatible Logitech devices
Flow is the shortest path when both computers run Windows or macOS and you already own supported Logitech hardware. Logitech says Flow moves control when the supported mouse reaches the edge of one screen; the keyboard follows to the other computer. The same feature set can copy text, images, and files between computers. This convenience is tied to the supported-device list, so a generic Bluetooth or USB mouse cannot be assumed to work.
Mixed Windows, macOS, and Linux systems
Start with Synergy or Deskflow, then check the exact operating-system builds before installation. Synergy is the commercial choice and advertises screen-layout configuration, hotkeys, clipboard sharing, and TLS/SSL encryption. Deskflow is the open-source project Synergy identifies as its upstream. The relationship does not guarantee identical installers, interfaces, release timing, or feature parity, so treat each project’s current documentation as authoritative for your machines.
Mac and Windows without a hardware lock-in
ShareMouse is designed for Mac and Windows and does not require a particular keyboard-and-mouse manufacturer. Its site describes local-LAN input sharing, clipboard support, file drag-and-drop, and optional AES encryption. Check the current personal-use freeware limits and license terms before deploying it on more than a casual home setup.
Windows-only desks
Mouse Without Borders is available through PowerToys and is a logical candidate when every computer is Windows. A secondary description reports support for up to four PCs and clipboard sharing, but those details can change with the PowerToys release. Confirm the current Microsoft documentation for installation, supported versions, pairing, and the number of computers allowed.
Rank #2
- Precision you can feel with the Haptic Sense Panel; customizable (1) haptic feedback on specific actions, shortcuts, notifications enhancing productivity on this wireless Bluetooth mouse
- Effortlessly access favorite tools with Actions Ring (2) on this MX Series mouse—a dynamic, customizable overlay adapts to each app, placing most used filters, adjustments, and shortcuts at your cursor
- Scroll 1,000 lines per second and stop on a pixel with the MagSpeed scroll wheel—Logitech’s fastest (3), quietest, and most precise (4) scrolling experience
- Enjoy 2X more powerful connectivity (7) with a USB-C dongle, advanced radio chip, and optimized antenna for faster, stronger, reliable performance—or use Bluetooth for more versatility
- Ergonomic mouse designed for comfort, MX Master 4 keeps you in flow with a natural tilt, intuitive buttons, and a thumb scroll wheel that reduces hand stress for fluid navigation
Early adopters and alternatives to investigate
Hydra’s project description lists Mac, Windows, and Linux support, movement across screen edges, encrypted relay connections, and file transfer. Those are project claims, not an independent assessment of maturity. Multiplicity is another Windows option; search results describe KVM-style switching and additional functions in higher tiers, but current limits and prices are not established here.
Installation and setup procedures
Set up Logitech Flow
- Install Logi Options+ on both computers.
- Pair the supported Logitech mouse with both computers, assigning the mouse to distinct device channels.
- Connect both computers to the same Wi-Fi or Ethernet network. Flow depends on that shared network path.
- Enable Flow in Logi Options+ and arrange the computers in the same left-to-right or right-to-left order as their physical screens.
- Move the pointer to the configured screen edge. The pointer should appear on the other computer and the keyboard should follow.
- Test a short text selection first, then an image and a small file if your workflow depends on those transfers. A successful pointer switch does not prove that every transfer type is enabled.
If Flow does not appear, check device compatibility before troubleshooting the network. Logitech’s supported-device list changes over time; the MX Master 4 is listed among supported devices in the available material, but verify that listing when you install.
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- Install the current Synergy release on every computer you want to control and confirm that each operating system is supported.
- Choose the computer that will physically host the keyboard and mouse and configure it as the input source. Configure the other computer or computers as destinations according to the installer’s current terminology.
- Place each computer in the on-screen layout that matches the desk. The layout is what tells Synergy which edge should transfer the pointer.
- Enable clipboard sharing only if your organization permits data to cross between the machines. Configure hotkeys if edge movement is inconvenient for your monitor arrangement.
- Turn on the product’s TLS/SSL option where available, and review the connection status on every computer.
- Allow the application through the operating-system firewall on the private network profile. Do not open broad inbound access on a public or guest network.
- Test pointer movement, keyboard focus, clipboard text, and any file workflow separately.
The product’s local-network design means a firewall, VLAN, guest Wi-Fi isolation, or endpoint policy can block connections even when both computers have internet access. Internet reachability is not the same as peer-to-peer reachability.
Set up Deskflow
- Download the current Deskflow build for each operating system from the project’s official release channel.
- Read the release notes for supported versions and known limitations before choosing one computer as the input host.
- Configure the host and client roles, then define the physical screen arrangement so the pointer crosses the intended edge.
- Apply the project’s current security and clipboard settings, and restrict connections to the private network addresses you actually use.
- Permit the required local-network traffic through each firewall and test with a non-sensitive clipboard item.
Deskflow is relevant when open-source licensing matters, but its current setup difficulty and feature parity with Synergy are not fixed facts. Recheck both before standardizing it for a workplace.
Set up ShareMouse
- Install ShareMouse on the Mac and Windows computers that will participate.
- Place the virtual monitors in the same arrangement as the physical screens.
- Confirm that each computer is on the same local LAN and approve the application in the private-network firewall profile.
- Enable clipboard sharing or file drag-and-drop only for workflows that need it.
- Enable optional AES-encrypted traffic if it matches your security requirements, then test whether the current edition supports the number of computers and transfer types you need.
- Review the current freeware and personal-use terms before using it commercially.
Set up Mouse Without Borders
- Install the current PowerToys release on each Windows computer.
- Open the Mouse Without Borders feature and follow Microsoft’s current pairing procedure on every machine.
- Arrange the computer tiles to match the desk and test edge movement.
- Test clipboard sharing with harmless text before moving work documents.
- Check the current Microsoft documentation for supported Windows versions, pairing security, computer-count limits, and any feature changes.
Network, security, and workplace-policy checks
Keep the computers on a reachable private network
Flow requires both computers on the same Wi-Fi or Ethernet network. Synergy and ShareMouse also describe local-network operation. A wired connection can simplify troubleshooting, but it does not override firewall or segmentation rules. Guest Wi-Fi commonly blocks client-to-client traffic; corporate VLANs may do the same intentionally.
Rank #3
- Mastered for Mac: With matching Apple finishes, Logi Options+ functions for macOS (1), USB-C charging while you work (cable not included), MX Master 4 for Mac makes for a perfect fit with your Apple setup
- Precision you can feel with the Haptic Sense Panel; customizable (1) haptic feedback on specific actions, shortcuts, notifications enhancing productivity on this wireless Bluetooth mouse
- Effortlessly access favorite tools with Actions Ring (2) on this MX Series mouse—a dynamic, customizable overlay adapts to each app, placing most used filters, adjustments, and shortcuts at your cursor
- Scroll 1,000 lines per second and stop on a pixel with the MagSpeed scroll wheel—Logitech’s fastest (3), quietest, and most precise (4) scrolling experience
- Ergonomic mouse designed for comfort, MX Master 4 for Mac keeps you in flow with a natural tilt, intuitive buttons, and a thumb scroll wheel that reduces hand stress for fluid navigation
- Confirm both computers have addresses on a network that permits peer communication.
- Use the private or trusted firewall profile, not a blanket rule that exposes the service on every network.
- Check whether endpoint security blocks background input-sharing services.
- On managed devices, ask the administrator whether software installation, clipboard transfer, or local listening services are allowed.
Interpret encryption claims correctly
Synergy advertises TLS/SSL encryption, ShareMouse advertises optional AES-encrypted traffic, and Hydra describes encrypted relay connections. These statements identify intended protection, not an independent security audit. Confirm the exact protocol, key-management behavior, certificate handling, and whether traffic remains on the LAN or passes through a relay before approving a sensitive environment.
Clipboard and file transfer expand the data exposure beyond keystrokes. If a machine contains regulated or confidential material, disable transfer features when they are unnecessary and use separate accounts or network segments where policy requires them.
Clipboard and file-transfer differences
Do not assume that “clipboard sharing” means every clipboard format or file type will work. Flow specifically describes copying text, images, and files. Synergy advertises clipboard sharing but does not, in the available description, promise the same file workflow. ShareMouse lists clipboard sharing and file drag-and-drop. Mouse Without Borders is described as supporting clipboard sharing, while Hydra’s project description includes file transfer.
- Text: the simplest test and the least likely to expose an application-specific format issue.
- Images: test a small image because some applications place several representations on the clipboard.
- Files: verify whether the tool copies the file itself, a path, or only text representing the path.
- Security: treat every transferred item as data leaving one computer and arriving on another.
Pointer movement, hotkeys, and screen layouts
Edge-of-screen movement is intuitive when the monitors are physically adjacent and aligned. It becomes awkward when one computer is below a laptop, behind a vertical display, or frequently used through a full-screen application. Synergy advertises configurable hotkeys as well as screen-layout configuration; other tools may expose similar controls under different names.
Define the layout from the operator’s viewpoint, not from the order in which the computers were installed. If the pointer disappears at an edge, the virtual arrangement is usually wrong or the destination is disconnected. A hotkey can provide a reliable escape route when a full-screen application captures the pointer.
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Rank #4
- Enhanced Connectivity: Includes a Logi Bolt USB-C receiver and new radio chip for 2x more powerful connectivity(1) with fully encrypted, FIPS-compliant connections for top-tier security
- High-quality, durable materials: This Logitech MX Master office mouse offers improved stain resistance(1) and is easier to clean, so you can keep it looking good for longer
- Tracks on any surface: Stop on a pixel every time with the 8K DPI Darkfield laser sensor; track with precision, even on glass(2) with this darkfield mouse
- MagSpeed scrolling: Glide through 1,000 lines per second or scroll line-by-line with pixel-perfect precision — experience effortless control with this advanced mouse
- Quiet, focused work: Quiet Click technology reduces click noise by 90%(3), creating one less distraction so you and your work neighbors can focus on work
Common failures and practical fixes
The pointer will not cross to the other computer
- Confirm both applications are running and that the destination computer is shown as connected.
- Check that both machines are on the same reachable LAN rather than isolated guest Wi-Fi.
- Review private-network firewall permissions and endpoint-security alerts.
- Correct the virtual screen positions and verify the intended edge.
The pointer moves, but the keyboard types on the wrong machine
- Click the destination desktop once and test in a plain text editor.
- Check whether a full-screen or elevated application is capturing input.
- For Flow, verify that the keyboard follows the mouse’s paired channel and that both devices are supported.
- Restart the sharing service on both machines after changing the layout or pairing.
Clipboard works but files do not
- Check whether the product and edition support file transfer rather than clipboard text only.
- Test with a small local file and a path containing no unusual permissions.
- Review security settings that may intentionally disable file movement.
- Use an approved file-sharing method when the software’s transfer behavior is unclear.
Connections drop or feel inconsistent
- Test both computers on Ethernet or a non-isolated Wi-Fi network.
- Look for sleep, VPN, firewall, or network-roaming events at the time of the disconnect.
- Keep the applications updated together when the vendor requires matching versions.
- Do not infer that a higher bandwidth internet connection will fix a blocked local route.
When a hardware KVM or display switch is still the right answer
Choose hardware when you must switch one or more displays as well as input, when the computers cannot share a network, or when workplace policy forbids software that captures and forwards keyboard and mouse events. Hardware also avoids dependence on background services, pairing state, and operating-system support. A practical hybrid is common: software sharing for keyboard and mouse, plus the monitor’s built-in input selector or a separate display switch for video.
Before buying or deploying anything, list the exact signals your displays use, the number of computers, refresh-rate requirements, USB devices beyond the keyboard and mouse, and whether audio or webcams must follow the active system. A software input-sharing tool addresses only the keyboard-and-mouse portion of that list.
A decision checklist
- List every operating system. Eliminate tools that do not support all computers, and verify Linux or mixed-platform support rather than relying on the word “cross-platform.”
- Check peripherals. Select Flow only when the current Logitech compatibility list covers your mouse and keyboard; otherwise favor tools designed for existing peripherals.
- Map the network. Confirm local peer connectivity, firewall permission, and workplace policy before installation.
- Define transfers. Decide whether you need text only, images, whole files, or drag-and-drop, and test that exact workflow.
- Set the security boundary. Compare LAN-only behavior, relay use, encryption claims, and independent policy requirements.
- Choose the switching model. Use edge movement for adjacent screens and hotkeys when the physical layout is irregular.
- Account for video. Add display switching or retain a hardware KVM if one monitor must change inputs.
- Verify current terms. Recheck release support, device compatibility, freeware limits, licensing, and tier features immediately before deployment.
Which option fits which desk?
Two computers, Windows and macOS, with supported Logitech gear
Start with Flow. It minimizes configuration and adds text, image, and file copying, provided the devices and network meet its requirements.
Windows, macOS, and Linux with a preference for commercial support
Evaluate Synergy first, then verify every operating-system version and your organization’s network rules. Its documented layout, hotkey, clipboard, and TLS/SSL features cover the usual multi-computer workflow.
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Evaluate Deskflow, but treat release support and setup effort as decisions to validate rather than assumptions inherited from Synergy’s feature list.
Best Value
- Logitech MX Master 3S Bluetooth Edition is a Bluetooth only mouse, and does not come with any USB receiver / adapter or charging cable
- 8K DPI Any-surface tracking: Use MX Master 3S cordless computer mouse to work on any surface - even glass (1) - with an 8000 DPI sensor with customizable sensitivity
- Quiet Clicks: MX Master 3S Bluetooth mouse with Quiet Clicks - offering the same satisfying feel but with 90% less click noise (2)
- Magspeed scrolling: A computer mouse with remarkable speed, precision, and near silence - MagSpeed scrolling is 90% faster (3), 87% more precise (4), and ultra quiet.
- Ergonomic design: Work comfortably with a precision mouse featuring a silhouette crafted for a more natural wrist posture and optimally placed thumb controls
Mac and Windows with file drag-and-drop
ShareMouse is a direct candidate because its product description includes LAN sharing, clipboard support, file drag-and-drop, and optional AES encryption. Confirm the current edition’s limits and licensing.
Several Windows PCs already managed with PowerToys
Mouse Without Borders is the natural first check. Follow Microsoft’s current documentation and verify the present computer-count and clipboard behavior instead of relying on older summaries.
A technically adventurous cross-platform setup
Hydra may be worth testing in a non-critical environment because its project claims cover all three major desktop platforms, edge movement, encrypted relay connections, and file transfer. Establish a rollback plan if release maturity or support is insufficient.
Bottom line
Software can replace a hardware KVM’s keyboard-and-mouse switching, not its video path. Choose Flow for compatible Logitech hardware on Windows and macOS; Synergy for a commercial cross-platform workflow; Deskflow for an open-source route; ShareMouse for Mac/Windows transfer features; and Mouse Without Borders for a Windows-only PowerToys setup. Treat Hydra as an emerging project and Multiplicity as an option requiring current feature and pricing verification. Whatever you choose, test the exact operating systems, network, firewall, transfer, and monitor workflow before retiring a hardware KVM.
Quick Recap
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