Head to head
Klar vs Inbox Zero
What actually differs: where each filter runs, who gets to read your mail, and what it costs.
| Aspect | Klar | Inbox Zero |
|---|---|---|
| Runs on | Your Mac | Inbox Zero's servers, or your own if you self-host |
| Who can read your mail | No one new. Your mail never leaves the device. | Full read and write access to your mailbox; message content goes to third-party AI providers |
| Works with | Apple Mail, with any account: IMAP, Gmail, iCloud, Exchange | Gmail, Google Workspace and Outlook accounts, in its own web app |
| Price | Free forever | From $18/month billed annually ($216 a year); no free plan |
Klar fits better when Spam is the problem, and you would rather not give a service permission to read, change and send mail from your mailbox
The honest picks
- Inbox Zero
- Not a spam filter: it is an assistant that sorts your inbox, drafts replies in your style, blocks cold outreach and unsubscribes in bulk. It is SOC 2 Type 2 certified, its source is public, and a self-hosted install can run against a local model. Pick it if you want that assistant across Gmail or Outlook and are comfortable with the access it needs.
- Klar
- Pick Klar if you read mail in Apple Mail and want a modern multilingual model that runs entirely on your Mac. No account, no cloud, nothing to hand over.
Product and price details from the vendors' public pages, July and August 2026: c-command.com, sanebox.com, support.google.com, learn.microsoft.com, libraesva.com, spamassassin.apache.org, rspamd.com, mailinblack.com, leavemealone.com, clean.email, getinboxzero.com, mailwasher.net. Klar is not affiliated with or endorsed by any vendor named here; names are used only to identify the products.
The on-device option
Free, private, in Apple Mail.
