0nbox
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Every inbox in one place. None of it on our servers.

0nbox is a free, private email aggregator. It brings every account you own, Gmail or any IMAP mailbox, into one list you can read, search and reply from. Your mail is stored in your browser, so there is no copy on our servers to leak, sell or hand over.

Create your private inboxSee how it works
Works withGmailAny IMAP mailbox
0copies of your mail
on our servers
1list for every
account you link
3 moof history fetched
on first load
$0to use, with no
card and no trial

Stop switching accounts to check your mail.

0nbox aggregates every linked mailbox into one list, newest first, ordered by when each message arrived. A thin colour rail marks the account it belongs to, so a work thread and a personal one stay apart without a folder tree or a second tab. When you want one account alone, filter to it from the sidebar.

Today, across three accounts

Hollis & Vane, quarterly filingwork · gmail
Re: the Tuesday walkthroughpersonal · gmail
Your domain renews in 30 daysside project · imap
Signed contract attachedwork · gmail

Search every account. Privately.

Type once and 0nbox searches subjects, senders and previews across every mailbox you have linked. The search runs against the copy of your mail in this browser, so what you look for is never sent to us or anyone else.

Search: “vane contract”

Signed contract attachedmatched the preview · work
Re: contract, clause 7matched the subject · work
Dinner with the Vanes?matched the sender · personal

From sign-up to one inbox in three steps.

  1. Step 1

    Create an account

    With an email and a password, or with Google. Google sign-in asks for your identity only, not your mail.

  2. Step 2

    Link your mailboxes

    Gmail links through Google's own consent screen. Any other IMAP account links with an app password. Add every address you have.

  3. Step 3

    Read them as one

    Your newest mail arrives first, straight into your browser's storage. 0nbox then works back through the last three months while you read.

Private by design, not by policy.

A privacy policy is a promise. Most of 0nbox’s privacy is a part that was never built: its server fetches your mail for your browser, and its database has no table to keep it in. The right-hand column is what that rules out.

What protects your mail

  • Mail kept in your browserMessages are stored on your device, and signing out deletes them.
  • Tracking pixels blockedRemote images stay unloaded, so a sender cannot tell when you opened their mail.
  • Encrypted credentialsApp passwords and Google tokens are sealed with AES-256-GCM and never returned to the browser.
  • Identity-only Google sign-inSigning in asks for your name and address. Reading mail is a separate consent.
  • Search on your deviceEvery account searched at once, without the query leaving you.

What it will never have

  • A copy of your mailOur server fetches your mail for your browser and has nowhere to keep it.
  • Analytics on your mailPage analytics are switched off on the inbox and on every message.
  • Your data for saleThere is no stored mail to sell, and no ad business to sell it to.
  • An admin over your accountThere is no role above yours, so nobody is granted your mailbox.
  • A team reading alongAn account belongs to one person and keeps belonging to them.

0nbox vs Spark, Shift and Mailbird.

All four put more than one email account in front of you. They differ on whether those accounts are truly aggregated into one list, what you have to install, and what it costs to add the second address.

0nbox compared with Spark, Shift and Mailbird
Feature0nboxSparkShiftMailbird
Every account in one listYes, newest firstYes, the Smart InboxNo, you switch between inboxesYes, a unified inbox
Several accounts on the free planYes, no limitYes, no limitYes, within the free plan's capsNo, one account
Paid plansNonePlus, Pro, EnterpriseAdvancedPremium, yearly or pay once
Where it runsYour web browserMac, Windows, iPhone, AndroidDesktop appWindows and Mac
Something to installNoYesYesYes

Competitor details from each product’s own website, checked 2 October 2026.

Which one fits

  • Choose Spark if

    You want native apps on your phone and your desktop, mail sorted for you, and tools for sharing drafts with a team.

  • Choose Shift if

    You want every web app, not only mail, in one desktop window, and switching between inboxes suits you.

  • Choose Mailbird if

    You want a traditional desktop client on Windows or Mac, and paying for Premium to add more accounts is fine.

  • Choose 0nbox if

    You have several Gmail or IMAP addresses and want them in one chronological list, in a browser, free, with no copy of your mail kept on anyone's server.

Mail in more than one Gmail account? Create your free inbox

Questions, answered.

What it connects to, where your mail lives, and what it costs.

0nbox is a free, private email aggregator that runs in your browser. It brings every email account you own into one list, newest first, that you can read, search and reply from, and it keeps no copy of your mail on its servers. It is built for one person with several addresses, not for a team.

An email aggregator collects mail from several email accounts into a single inbox, so you read everything in one place instead of signing in to each account in turn. Many web-based aggregators sync your mail through their own servers. 0nbox aggregates in your browser instead, so the combined inbox exists only on your device.

In your browser. When you open 0nbox, its server connects to your provider, fetches your messages and hands them to your browser, which keeps them in local storage. 0nbox keeps no copy of your mail. Each browser you sign in from holds its own copy, and signing out deletes it.

Your mail passes through 0nbox's server on its way from your provider to your browser, because a browser cannot connect to a mail server by itself. It is relayed, not kept: the database has no table for messages, and the request log masks the recipients, subject and text of anything you send.

Yes. Link each Gmail account through Google's consent screen, or with an app password, and its mail joins the same list. Every message carries a thin colour rail for the account it arrived in, and the sidebar filters the list down to a single account when you need it.

Gmail, and other providers over IMAP with an app password. Outlook and Microsoft 365 do not work yet: Microsoft blocks password sign-in over IMAP, and the OAuth route it requires is not built. Zoho only allows IMAP on its paid plans.

Your app passwords and Google tokens are encrypted with AES-256-GCM before they are stored, and they are never sent back to the browser or written to a log. Signing in with Google asks only for your name and address; reading mail is a separate consent you give when you link a Gmail account.

Yes. Remote images in a message are replaced with a placeholder, so a sender cannot tell when you opened it. You can load a message's images once, or trust the sender so their images always load.

Spark and Mailbird are apps you install, and Mailbird's free plan holds one account. Shift is a desktop browser where each inbox stays separate and you switch between them. 0nbox runs in your browser with nothing to install, aggregates every account into one list on the free plan, and keeps no copy of your mail on a server. Spark has phone apps and Outlook support, which 0nbox does not yet.

Nothing. 0nbox is free to use, with no trial period, no card to enter and no limit on how many mailboxes you link.

Free. Every account, every feature.

No trial clock, no card, no seat count. Link as many mailboxes as you have, and use everything on this page with all of them.

$0no card required
0nbox

All your email in one place. Only on your device.

Create an account, link your first mailbox, and read your newest mail in the same sitting. Free, with no card, and no copy of it on our servers.

Create your private inboxI already have an account