Measured on real mail 94.3%

Noise in.
Signal out.

Sorts your mail into five lanes and tells you why — on the web, macOS and Windows. Other AI agents act on your behalf. Klorn decides what deserves your attention and acts only by rules you set.

Start free ↗

Free, AGPLv3. The app signs in to your Klorn account — create one in about a minute. First-launch note ↗

Sorting this morning's inbox 0 of 64 · running
PUSH
0

Interrupts you now

QUEUE
0

Read it today

SILENT
0

Filed, not deleted

AUTO
0

Handled without you

Real classifier output on a hand-labeled inbox — 3 of 64 needed you.

Live A working replica — click the tiers, the rows, reply, re-file. The screenshots further down are the shipping app itself.

Inbox
The actual app

Close enough
to read.

Klorn sits in one native line at the top of your screen. Expanded, this is what it shows you — and everything you are allowed to change about it.

A push message with its evidence: why it was ranked, the deadline, and the one-key reply actions

Each shot is produced by KlornMac --render-previews, which draws the shipping SwiftUI views straight to disk. If a screen changes, the picture changes with it — there is no separate marketing asset to fall out of date. Read the app source →

A day with it

Three moments,
and only one needs you.

Klorn is not something you open. It runs against your inbox all day and asks for you exactly once — when a message genuinely cannot be answered without you.

Morning

Already sorted

Overnight mail is in its tier before you sit down, each one carrying the reason it landed there. Sixty-four messages, three that were yours.

While you work

One line, no banners

Klorn stays a single native line at the top of the screen. Queue, Silent and Auto never interrupt — only a real Push does, and you set what counts.

When you reply

Three drafts, your call

Accept, decline or ask — one key each, in your tone and the sender's language. Nothing sends itself; every send mints a receipt.

Where we disagree

Four opinions most
email AI doesn't hold.

These are choices, not features — each one costs Klorn something. Set against what the assistant already bundled with your mail decides to do instead.

KKlorn
—The assistant in your inbox
01 · Who decides

Sorts and drafts, then stops. Every send, delete and forward waits for you and mints a receipt.

01 · Who decides

Acts on your behalf and tells you afterwards. Undo is the safety net.

02 · What you see

Four fixed tiers, and the reason on every message. Move one and the classifier learns.

02 · What you see

Priority flags and unlimited labels. No reason given, and nothing to correct.

03 · What it claims

94.3% on a hand-labeled set that ships in the repo, cold and warm reported separately.

03 · What it claims

"AI-powered." No number, no eval set, no way to check it yourself.

04 · If you want out

AGPLv3. Read it, self-host it against your own keys, or fork it and leave.

04 · If you want out

Closed. Your mail is the training surface, and export is the only exit.

Measured, not promised

Numbers from a real inbox.

Every release is scored against a hand-labeled set of real emails before it ships. These are the latest numbers, and the eval set is in the open repo.

94.3%
Real-mail accuracy

50 of 53 hand-labeled real emails sorted into the right tier.

95.5%
Silent precision

When Klorn files mail as noise, it almost never buries a real signal.

0
Unapproved actions

Every send, delete and forward waits for you and logs a signed receipt.

Measured July 2026 on a 53-email hand-labeled set from a live inbox, warm-start with learned context (cold-start: 81.1%). Methodology and eval set →

Works with

Check this before
you download.

Klorn reads your mail, so what it connects to is the first thing worth knowing — including what it does not connect to yet.

GmailGoogle sign-in. Multiple inboxes on Pro.
Naver MailConnected over IMAP from Settings.
Google CalendarRead, and create events on your say-so.
macOS 14+Universal — Apple Silicon and Intel.
Any mail languageReplies come back in the language the mail arrived in.

Not supported: IMAP hosts other than Naver. Signing in to Klorn is Google-only, and there is no native mobile app — mobile runs in the browser today. Klorn's own interface — menus, notifications, its own words — is English and Korean only, whatever language your mail is in. On Windows the desktop app is an unsigned beta (SmartScreen warns once); on Linux, Klorn runs in the browser. Self-hosting works against your own database and model keys.

Coming soon: Outlook & Microsoft 365 and iCloud Mail — already built, staged for rollout after security review. Sign in with Apple and Naver is planned on the web, the Mac app and mobile alike, so one Klorn account covers every device, and native mobile apps are on the way. Planned, but not built yet: the interface in Spanish, French, Japanese and more — unlike the providers above, there is no code for it today. None of it has shipped; this page is where it lands when it does.

Open source

Read it. Run it yourself.
Leave whenever you like.

An email agent sees everything you receive, so "trust us" is not an answer. The classifier, the prompts and the eval set are all in the repo.

View the repository ↗ See the eval set
Pricing

Start free. Upgrade when
Klorn acts for you.

Sorting is free forever. You only pay once Klorn starts drafting and sending on your say-so — the part that costs real money to run.

Free

The firewall

$0/month

No card. A daily AI budget keeps it sustainable.

  • Five-lane mail firewall — only real signals interrupt you
  • Decision queue with evidence for every card
  • Morning briefing and calendar view
  • Assistant that answers from your own mail
Start free
Founding price

Klorn Pro

$8.99/month

7-day Pro trial, then $8.99/mo on the web. Cancel anytime.

  • Everything in Free, with a bigger AI budget
  • Reply drafts you approve and send from Klorn
  • Create calendar events by voice or chat
  • Multiple Gmail inboxes, auto-handled noise
Start 7-day Pro trial ↗
Before you ask

The ones we
actually get.

Why does Google warn me when I sign in?

Reading your mail needs Google's restricted scopes, and those need a security review before an app is marked verified. Until that clears you see an unverified-app screen once, and the beta is limited to the first 100 accounts.

Can it send something without me?

No. Send, delete and forward always wait for an explicit approval and each one writes a signed receipt with a hash of exactly what went out.

Where does my mail actually go?

To the classifier and back. Your OAuth tokens are encrypted at rest, and because the whole thing is AGPLv3 you can read the code that touches them — or run it yourself.

What if it files something wrong?

Move it. Every message shows why it landed where it did, and the correction is what the classifier learns from — that is the difference between 81.1% cold and 94.3% warm.

When is the Windows app?

Shipped, as an unsigned beta — SmartScreen warns once until the app is code-signed. The web app remains available in any browser with the same account and tiers.

Can the AI run up a bill?

No. Klorn caps its own spend per day, and stops rather than overspending — a runaway loop costs you nothing. That cap is why sorting stays free.

The next inbox is
a decision queue.

Free while the beta runs — the first 100 accounts, until Google's review clears.

Start free ↗ Download for Mac

Already approved? Log in · macOS 14+ universal · Windows in the browser · AGPLv3