About RealtimeClipboard

Why it exists

Moving a paragraph from a work laptop to a personal phone is a solved problem only if both devices happen to agree on an ecosystem. Apple devices have Universal Clipboard, and it stops at the edge of Apple. Local tools like Snapdrop need both machines on the same Wi-Fi, which rules out a phone on mobile data, a locked-down office network, or a machine two countries away. Everything else ends up being the same workaround: email it to yourself, or paste it into a chat with yourself, and let a company you did not choose keep a copy forever.

RealtimeClipboard is the narrow answer to that. You open the same short key on two devices and they share a clipboard. There is no account to make, nothing to install, no network requirement beyond both devices being online, and no copy left behind when you close the tab.

How it works

What you copy is encrypted in your browser with AES-GCM before it leaves the machine, using a key derived from the short session key you type. That session key is never transmitted. The server receives a SHA-256 hash of it, which is enough to know which room to forward a message to and not enough to open one, plus ciphertext it has no way to read.

The relay holds messages in memory for the moment it takes to pass them on and writes nothing to disk. Files skip the server entirely — they travel directly between your devices over WebRTC, so a large transfer costs the service nothing and never exists anywhere in the middle. A session can be locked with a PIN, which is also never transmitted.

None of that requires trusting a description of it. The full source is public, the wire protocol and threat model are written down in the repository, and the relay is a separate service that shares no code with the browser — only the documented protocol.

What it will not do

A short list, because what a product refuses is more informative than what it promises:

It will not merge two people typing at once. Conflict-free collaborative editing is a real and heavy piece of engineering, and this is a clipboard. When two devices type together you see the other caret coming in its own colour, and an arriving clip is offered rather than silently applied over your work.

It will not remember you. No account, no email, no profile, no server-side history. Settings and clipboard history live in your own browser storage and are never uploaded. This is also the honest cost of the design: lose the key and there is no reset link, because there is nothing on the server that knows the session was yours.

It will not pretend the key is more than it is. The share key is a bearer credential — anyone who has it can read the session, which is exactly what makes a five-character key with no login possible. That trade is documented rather than hidden, and a PIN lock exists for when it is the wrong trade.

It will not sell what you paste. It could not: the contents are encrypted before they are sent and the server has no key.

How it is paid for

The relay is a rented server with a real monthly bill, and there is no subscription, no paid tier and no account to attach one to. A single ad slot below the editor, served by Google AdSense, is what covers it.

It is worth being precise about what that means, since the two claims sit next to each other. An ad tag is third-party code running inside the page, and in the app that page is the one showing your decrypted text — so Google's script runs where that content is visible, the same as any script on any page. What it does not get is your session key: the app strips the key out of the address bar before the ad tag is allowed to load at all. The encryption between your devices and the relay is unaffected either way. The privacy policy sets out the whole of it, including what Google Analytics sees.

Who builds it

RealtimeClipboard is made by Akshay Nikhare, a software engineer, and published by CadNative. It is not a venture-funded company and there is no team behind it — it is one maintainer, which is the reason the scope stays this narrow and the reason a bug report gets read by the person who can fix it.

The project is open source under the MIT licence. It ships as four things from one codebase: the web app, this site, a Node command-line client, and a desktop build for Windows, macOS and Linux. Contributions, bug reports and security disclosures are all welcome — see the repository for how the code is laid out and what the rules are.

Getting in touch

Questions, corrections, press and business enquiries all go to info@realtimeclipboard.com. Bugs and feature requests are better as GitHub issues, and security problems have their own private route. The contact page has the detail, including what to expect and how long it takes.

If something on this site is wrong, say so. It gets fixed and the change is in the public history.