Every time everyone is free, as a paste-ready list.

OpenSlot is a scheduling tool for Microsoft 365: a web app and an Outlook add-in that turn Outlook calendars into a paste-ready list of free times. Pick people, a timezone and a window of days or weeks; OpenSlot reads everyone's free/busy and returns one list of every slot where all of them are free, grouped by day, ready to paste into an email, a Teams chat or a candidate offer. It is made by OpenSlot LLC.

Scheduling Assistant reads the same Microsoft 365 free/busy, but it is a grid for booking one internal meeting now and has no way to export what it shows. Scheduling Polls, which replaced FindTime, asks attendees to vote on candidate times, which adds a round of waiting. OpenSlot computes every time the people you pick are all free, across up to 40 calendars and 60 days on Pro, and gives you the answer as plain text you can send to anyone, including clients and candidates outside your company. The Assistant is still the right tool for booking an internal meeting on the spot, and a poll for a time the group should decide.

Every new account starts with 14 days of Pro, with no card required. After that, the Free plan covers you plus 1 person per lookup and a 7-day window. Pro is $7 per user per month, or $72 per user per year ($6 a month), for up to 40 people per lookup and a 60-day window. Team is $5 per user per month, or $48 per user per year, with a 5-seat minimum; volume pricing lowers the monthly price to $4 per user for 25–99 seats and $3 for 100 or more. Prices are in US dollars, and you can cancel any time.

The web app needs no install: sign in at useopenslot.com with a Microsoft 365 work or school account that has an Exchange Online mailbox. For the Outlook add-in, open a new email in Outlook, choose Apps (or Get add-ins), search for OpenSlot and select Add, or click Get it now on its Microsoft Marketplace listing. It works in Outlook on the web, Windows, Mac and the new Outlook. IT admins can deploy it to everyone from the Microsoft 365 admin center under Settings, then Integrated apps.

Yes — there's a recording of the real add-in further up this page, under “See it work”. It runs the whole loop inside Outlook: open OpenSlot on the email you're writing, pick a window, and the times land in the body.

It depends on your company's settings. OpenSlot asks only for delegated, read-only permissions, which employees can approve themselves wherever their organization allows it. Many organizations turn that off; then an admin approves it once, for everyone, with one click from our Security & IT page.

Free/busy — the same blocks the Scheduling Assistant shows. For calendars you can already see in detail, Microsoft includes meeting subjects and locations in the same response; OpenSlot uses only the free/busy and discards the rest. It never asks for event bodies, attendees or attachments, and availability is computed per request and never stored.

Yes, for the person you're sending times to: they get plain text in your email, so they need no account, nothing to install and no Microsoft — a client on Gmail is fine. (Free and trial lists end with one short line linking to OpenSlot.) The limit is whose calendar OpenSlot can read. That's your own organization, because free/busy has to be shared with your Microsoft 365 account.

Anyone in your organization whose free/busy you're already allowed to see, up to 40 people per lookup on Pro, or you plus one other person on the free plan. People outside your org are skipped with a note.

Yes — the Outlook add-in puts an "Insert free times" button in the compose toolbar (web, Windows, Mac, new Outlook). The list drops in at your cursor, formatted.

Your account simply drops to Free (you + 1 person, 7-day window). No card is taken for the trial, so nothing is charged. Upgrade whenever a lookup needs more. Free and trial lists end with a one-line "made with OpenSlot" link; paid plans remove it.

Manage billing → Cancel plan. You keep access until the end of the period you paid for. No emails, no calls.