Which software KVM for two PCs on one desk?
Five tools move one keyboard and mouse between computers: DeskStitch, Mouse Without Borders, ShareMouse, Synergy 3 and Deskflow. They differ in price, in how many machines they handle, and in one thing that decides most desks: whether screens are placed by pixels or by their real size.
Four of the five arrange screens on a pixel grid. That is correct while every monitor has the same resolution and scaling, and wrong the moment a 4K screen stands next to a 1440p one: the cursor arrives at the wrong height, stops at an invisible wall where the taller pixel edge runs out, and moves at a different speed on each PC. DeskStitch is the one that reads each monitor’s physical size and lays the desk out in millimetres. That is its whole reason to exist, and it is also why it does less than the others everywhere else.
| DeskStitch | Mouse Without Borders | ShareMouse | Synergy 3 | Deskflow (was Barrier, Input Leap) | |
|---|---|---|---|---|---|
| Screen layout | Millimetres, from each monitor’s own physical size | Machine grid, screens placed by pixels | Monitor Manager, screens placed by pixels | Screen grid, pixel edges | Grid of named computers, pixel edges |
| A 4K next to a 1440p | Edges line up 1:1, no dead zone, same cursor speed | Dead zones and a speed difference; a relative-mouse mode softens it | Pixel edges; “size compensation” only in the Pro edition | Pixel edges, dead zones with mixed sizes | Pixel edges, dead zones with mixed sizes |
| Number of PCs | Two: one host, one client | Up to four | Free and Standard two, Pro up to nine | Lite three, Plus five, Max fifteen | Many |
| Platforms | Windows 10 and 11, x64 and ARM64 | Windows | Windows and macOS | Windows, macOS, Linux | Windows, macOS, Linux, FreeBSD |
| Price | 29 USD once, after a 7-day trial | Free, open source, part of PowerToys | Free edition, Standard 99.95 USD, Pro 149.95 USD | Lite 15 EUR, Plus 19 EUR, Max 29 EUR, one-time | Free, GPL |
| Account | None; a license key is entered in the app | None | Online license authorization | Symless account for the license | None |
| Clipboard | Text and images | Text and files | Text and images, not in the free edition | Yes | Yes |
| File drag and drop | No | Yes | Yes | Yes | Yes |
| Source code | Closed | Open | Closed | Closed | Open |
| Where it stands | Maintained, releases at deskstitch.com | Maintained by Microsoft inside PowerToys | Commercial, long established | Commercial, two decades old | Deskflow active; Barrier dormant; Input Leap archived July 2026 |
Prices and limits checked September 2026 from each vendor’s own pages. Found something out of date? Tell us and it gets corrected.
Pick by what is on your desk
- A Mac, a Linux box or a BSD machine is on the desk
Synergy 3 or Deskflow. DeskStitch has no build for them and none is planned. - Three or more computers
Mouse Without Borders if they are all Windows and free matters, Synergy 3 otherwise. DeskStitch does exactly two. - Two Windows PCs, and every screen has the same resolution and scaling
Mouse Without Borders. It is free, it is from Microsoft, and the pixel grid is not lying to you at that desk. - Two Windows PCs, and a 4K, 1440p, ultrawide or portrait screen sits next to a different one
DeskStitch. This is the case it exists for: screens placed in millimetres, so the edges meet and the cursor keeps its speed. - You need to drag files between the two PCs
Mouse Without Borders, ShareMouse or Deskflow. DeskStitch shares the clipboard, including images, but not files. - Free and open source matters more than anything else
Deskflow, which is where Barrier and Input Leap ended up. - You want no account anywhere and no subscription
DeskStitch or Mouse Without Borders. ShareMouse authorizes online and Synergy needs a Symless account.
The detailed comparisons
Questions
Which software KVM is best for two PCs with monitors of different resolutions?
DeskStitch, because it is the only one of the five that places screens by their physical size in millimetres instead of by pixels. The others hand the cursor over at a pixel edge, which leaves a dead zone and a different cursor speed on each PC when a 4K screen sits next to a 1440p one. If your screens all share one resolution and scaling, that advantage disappears and the free tools do the same job.
What is the best free alternative to ShareMouse or Synergy?
Mouse Without Borders for Windows-only desks, because it is free, made by Microsoft and installed with PowerToys. Deskflow if a Mac or a Linux machine is involved; it is the maintained successor to Barrier and Input Leap, which are dormant and archived.
Can one keyboard and mouse control a Windows PC and a Mac?
With Synergy 3, ShareMouse or Deskflow, yes. Not with DeskStitch or Mouse Without Borders, which are Windows only.
Is a software KVM the same as a KVM switch?
No. A hardware KVM switch routes the video and USB of both PCs through a box, so one set of monitors shows one PC at a time. A software KVM leaves each PC on its own monitors and passes the keyboard and mouse over the network, so both stay visible. The longer answer is in the guide on software KVM versus hardware KVM.
How much does DeskStitch cost compared with the others?
29 USD once, after a free 7-day trial, and only for the PC with the keyboard and mouse. Mouse Without Borders and Deskflow are free, Synergy 3 is 15 to 29 EUR once, and ShareMouse is 99.95 USD for the Standard edition and 149.95 USD for Pro.
Try it on your own desk
Free for 7 days on both PCs, nothing to sign up for. If it does not earn its place, uninstall it.