Anti-spam for Apple Mail.
Private, secure and on your Mac.
Still deleting spam by hand?
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- 100+
- languages
- Instant
- filtering
- 100%
- on-device
How it works
- 01
Install
Install from the App Store, switch it on in Mail. No account, no cloud, no setup.
- 02
Filtered on arrival
Klar checks each message the moment it arrives and moves spam and phishing to Junk. Automatically, in the background.
- 03
Your own AI, with Klar Plus
Move a message where it belongs and Klar Plus learns from it on the spot. An AI shaped by your mail, that never leaves your Mac. See Klar Plus
The engine
One model, on your Mac.
Type or paste any email. Klar sorts it into Inbox, Marketing, or Junk, like it would in Mail. Moving spam to Junk is automatic and free; the Marketing folder is Klar Plus.
* A dedicated Marketing folder requires Klar Plus, an optional paid add-on. Spam filtering is free forever.
Klar Plus
Your personal spam AI learns from your email.
Klar Plus shows every decision it makes, with how sure it was. Disagree with one? Drag the message where it belongs. The AI learns from that correction on the spot, on your Mac, and it is yours alone.
Klar Plus is an optional add-on, coming soon.
Accuracy and privacy
Everyone trades accuracy for privacy. Klar refuses to.
Cloud filters are accurate because they read your mail on their servers. On-device filters stay private but basic. Klar runs a modern multilingual transformer, cloud-grade AI, entirely on your Mac. Both, finally.
Private by architecture, not by promise.
The part of Klar that reads your inbox has no network access at all. By construction, it cannot send your mail anywhere: it is filtered on your Mac, never on a server. Built and based in the EU, and the only things we host, like this website, run on EU servers.
Where Klar fits
| Category | Where your mail is read | The intelligence |
|---|---|---|
| Cloud filters | On their servers | Large models, trained on everyone's mail |
| Classic Mac filters | On your Mac | Word statistics you train yourself |
| Klar | On your Mac | A modern multilingual AI model |
For the nerds
- Model
- XLM-RoBERTa, a 550M-parameter multilingual transformer, paired with a fast on-device classifier that learns your inbox.
- Speed
- Instant. Every message goes through the neural model as it arrives, in the background, without slowing Mail down.
- Languages
- 100+ languages supported natively. No configuration needed. The model detects the language automatically.
- Privacy
- Every email is classified on your Mac. Nothing is sent to a server. No cloud, no API calls, no telemetry.
- Learning
- Learns instantly. Every correction updates the model on the spot, on-device. A nightly pass re-checks older mail so your first days stay fast.
- Accuracy
- Classifies into 4 categories (spam, regular mail, marketing, gibberish) with three sensitivity profiles you control (Cautious, Standard, Aggressive).
Frequently asked
How do I check Klar is registered in Apple Mail?
Two ways. In Mail, open Settings → Extensions. Klar should be in the list with its checkbox ticked. Or from Terminal: pluginkit -m -i im.klar.Klar.KlarMailExtension. A leading + means the extension is registered and enabled.
Which mail accounts does it work with?
Anything Apple Mail reads: iCloud, Gmail, Fastmail, Outlook, custom IMAP. Klar classifies the messages Mail shows you, regardless of provider.
Does it slow Mail down?
No. Klar checks mail in the background, so Mail stays fast. Checking a message takes a few hundredths of a second.
Does Klar send my emails to a server?
No. The model runs on your Mac. No cloud, no API calls, no telemetry. See our Privacy Policy.
Which languages are supported?
100+ languages out of the box. The model detects the language automatically. No configuration.
What if Klar misclassifies a message?
Drag it back (Junk → Inbox or Inbox → Junk) and the message moves to the right folder. With Klar Plus, that correction retrains the filter and a nightly pass re-checks older mail, so the next similar message lands where it should.
Should I turn off Apple Mail’s own junk filter?
Yes, for the cleanest results. Open Mail → Settings → Junk Mail and turn off Enable junk mail filtering, so Klar is your only inbox filter and two filters don’t disagree. This affects your Mac only: mail your provider already moved to Junk on its own servers is handled separately.
Reclaim your inbox
Spam filter for Apple Mail. Free on the App Store.
Requires macOS 14 Sonoma or later.