LinkedIn's messaging interface is terrible. You already know this. If you send more than 20 DMs a day, you know it in your bones. No keyboard shortcuts. No snooze. No labels. No way to tell a hot lead from a recruiter spam message from a "congrats on the work anniversary" notification. Everything lives in one flat, unorganized list.
I saw Kondo — the "Superhuman for LinkedIn" — and thought: this is a real product solving a real problem. Their reviews are genuinely incredible. People love it. The Head of Growth at actual Superhuman uses it. That tells you something.
But Kondo starts at $28/month. And I thought: what if someone built this as a free Chrome extension? No servers. No accounts. No monthly fee. Just a fast keyboard-driven inbox that stays in your browser.
So I built it. It's called SuperLinkin, and it's free. Here's the story.
LinkedIn has 1 billion users. A significant percentage of them — salespeople, recruiters, founders, creators — use DMs as a primary business tool. They close deals in DMs. They source candidates in DMs. They build partnerships in DMs.
And LinkedIn gives them... this:
If you are an SDR handling 50+ conversations, or a recruiter managing candidate pipelines, or a founder doing outbound sales — this is not a minor inconvenience. It is a daily tax on your time and your ability to respond quickly. And responding quickly is the whole game.
Kondo is a good product. I want to be clear about that. They validated the category, built a loyal user base, and their reviews speak for themselves.
But three things bothered me:
$28/month for Basic. $36/month if you need Sales Navigator support. $52/month if you want CRM sync. For a team of five salespeople, that is $2,160 to $3,120 per year — for what is ultimately a UI layer on top of LinkedIn.
I kept thinking: does this need to cost money? The core features — keyboard shortcuts, labels, snooze, split inboxes — are all things that can be built as a Chrome extension using local browser storage. No server costs. No infrastructure overhead.
Kondo is a web app. You log in at app.trykondo.com and it talks to LinkedIn on your behalf. That means your LinkedIn session data passes through their servers. They say they process it locally, but the architecture inherently requires trust.
I wanted to build something where trust is not required. If all the data stays in your browser and the extension only talks to LinkedIn directly (using your existing session cookies), there is nothing to trust. You can verify it yourself by reading the network tab.
Kondo reportedly has around 7,000 users. The addressable market — people who use LinkedIn DMs for business — is in the tens of millions. This is not a winner-take-all market. There is room for a free alternative that serves the large population of individual users who want a better inbox but do not want to (or cannot) pay $28+/month for it.
I kept the architecture deliberately simple:
The extension does one thing: it piggybacks on your existing LinkedIn session cookies to make authenticated requests to LinkedIn's internal Voyager API. When you are logged into LinkedIn in the same browser, the extension can fetch conversations, read messages, send messages, and mark things as read.
The web app is a React frontend that communicates with the extension. It provides the UI — the split inboxes, the keyboard shortcuts, the dark theme, the command palette.
All custom data — labels, snooze times, notes, stars — lives in chrome.storage. Nothing leaves your browser. There is no backend. No database. No authentication system. No user accounts.
What this means for you: Install the extension, open the app, and start messaging. No sign-up. No onboarding call. No credit card. It just works.
Why Chrome's Voyager API instead of scraping the DOM?
Many LinkedIn extensions work by injecting JavaScript into the LinkedIn page and manipulating the DOM. This is fragile. Every time LinkedIn changes their HTML structure (which happens constantly), the extension breaks. By using the Voyager API directly, the extension is decoupled from LinkedIn's frontend. It is more reliable and significantly faster.
Why local storage instead of a cloud database?
Two reasons. First, privacy — your LinkedIn messages contain sensitive business information, and they should not live on someone else's server. Second, cost — no servers means no hosting costs, which means the tool can be free without requiring venture funding or a premium tier to sustain it.
Why a separate web app instead of an overlay on LinkedIn?
LinkedIn's DOM is slow. Injecting a complex UI on top of it creates performance issues and visual conflicts. A dedicated web app has full control over the rendering pipeline. The result is a UI that feels fast — keyboard shortcuts respond instantly, scrolling is smooth, and there are no layout shifts from LinkedIn's own JavaScript fighting for control.
The feature set is intentionally focused on the things that make the biggest difference:
J/K to navigate, Enter to open, E to archive, H to snooze, L to label, S to star, R to reply, C to compose, / to search, Cmd+K for the command palette. If you have used Superhuman, you will feel at home.There is no public API for LinkedIn messaging. The Voyager API is internal and undocumented. But it follows consistent REST conventions, and once you understand the entity URN format (urn:li:fsd_profile:ABC123), the patterns are predictable. The main risk is that LinkedIn changes endpoints, but the core messaging endpoints have been stable for years.
Manifest V3 replaced background pages with service workers, which have no persistent state. This means you cannot keep a long-running connection open. Every action is request-response. For a messaging tool, this means you poll for new messages rather than streaming them. The UX trade-off is acceptable — messages appear within seconds, not instantly — but it is a constraint worth knowing about.
Superhuman exists because Gmail's UX got bloated. Kondo and SuperLinkin exist because LinkedIn's messaging UX was never good to begin with. This is a reliable pattern for indie products: find a tool that millions of people use daily but hate using, and build a better interface for it. The market is pre-validated by the original product's user base.
Kondo charges $28-52/month. I could charge less and compete on price. But free changes the conversation entirely. Free means no friction to try it. Free means every sales team can adopt it without getting budget approval. Free means word of mouth compounds because there is zero risk in recommending it to a colleague.
The trade-off is obvious: no revenue from this product (for now). But my goal is distribution first. Get the tool into enough hands, and monetization options emerge — premium features, team plans, integrations, whatever makes sense. The Superhuman playbook is: be indispensable first, charge later.
There are very few tools in this space. That surprised me.
The market is surprisingly uncrowded for something that millions of people need.
SuperLinkin is live and free. Here is what I am working on next:
{first_name} auto-fill.If you use LinkedIn DMs for work and you have ever wished the inbox was not terrible, I would genuinely appreciate it if you tried SuperLinkin and told me what is broken. The best product feedback comes from people using the tool for real work, not from surveys.
Keyboard shortcuts, split inboxes, true snooze, labels, search, and a dark theme. Everything stays in your browser. No servers. No tracking. No cost.
Get SuperLinkinFor the technical readers: The extension uses Chrome MV3, React for the web app, Zustand for state management, and chrome.storage for persistence. All communication between the web app and extension happens via Chrome's messaging API. If you are curious about the architecture, reach out — happy to talk shop.
Published March 2026. If you have questions or feedback, reach me at hello@appstronauts.shop.