Arkpine SoftwareGuides · Updated November 2026
SlotKeeper
A Google Forms™ sign-up sheet where full slots disappear
Make one multiple-choice or dropdown question whose choices are the slots, ask for each person's name, and give every slot its own limit with SlotKeeper: a slot is removed from the form a few seconds after the response that fills it. Google Forms™ alone cannot hide a full slot, so without an add-on you remove it yourself.
Free for one limited question per form, with any number of slots and sign-ups. Pro from $29.99 a year.
Build the form
- Who is signing up
Add a required short-answer question for the name. For a reply address, turn on collecting email addresses under Settings, Responses.
- One choice per slot
Add a multiple-choice question, or a dropdown for a long list, with one choice per slot. Write the day in each: "Tue 12 Nov, 9:00 to 9:30", not just "9:00".
- Say what happens next
Under Settings, Presentation, edit the confirmation message: where to come, what to bring, whom to tell if plans change.
- Set the limits
Open SlotKeeper from the form's add-ons menu, tick the slot question, type a limit next to each slot and press Save.
Tips that save trouble later
- Each slot can have its own size. 1 for a one-to-one meeting, 20 for a workshop. A slot left without a limit stays open.
- Do not rename a slot once people have picked it. A response stores the text the person chose, so a renamed slot no longer matches its earlier answers.
- When everything is full, the question shows one line you word yourself, such as "No places left", and the form can close by itself.
- Your roster is the form. The Responses tab, or a spreadsheet linked to it from the Responses tab, lists who took which slot.
- Two limited questions, such as a slot and a T-shirt size, or a checkbox question so one person can take several slots, need Pro.
Without an add-on
There are three ways that use only what Google gives you, each with a catch:
- Watch and delete. Link a sheet, count each slot with
COUNTIF, and delete a slot from the form when it is full. It works if someone is watching; a busy sign-up fills while you are away. Step by step - A shared sheet. People type their name next to a slot in a Google Sheets™ spreadsheet shared for editing. It is simple and everyone sees who signed up, but nothing stops extra names, and anyone who can edit can change or delete someone else's.
- Google Calendar's appointment schedules, if every slot is a meeting with you: people book a free time in your calendar. Which features you get depends on your Google account.
Free and Pro
Free: one limited multiple-choice or dropdown question per form, any number of slots and sign-ups, no time limit and no sign-up. Removing full slots, putting them back, closing the form and the alerts are all free.
Pro, $29.99 a year or $79 lifetime: any number of limited questions, checkbox questions, places left shown in the slot text such as "Tue 9:00 (3 left)", and closing the form after a total number of responses. If a yearly key ends, what is already set up keeps working.
Where the limits are
- A few seconds of overlap. A slot is removed a few seconds after the response that fills it. Two people who submit within those seconds can both take the last place. SlotKeeper cannot prevent this; it lists the late answers by time in its panel and emails you.
- Cancellations are not instant. Google Forms™ has no event for a deleted response, so a freed place comes back at the next submission, at the hourly check, or when you open the panel.
- About ten limited forms per Google account at once, because of Google's limits on add-on triggers.
- If an update fails, you hear about it. Google sends no email when an add-on's automatic update fails, so SlotKeeper emails you itself, and an hourly check repairs what it can.
Questions
How do I make a sign-up sheet in Google Forms™?
Add a question for each person's name, then a multiple-choice or dropdown question with one choice per slot. To stop a slot from filling past its limit, set a limit per choice with an add-on such as SlotKeeper, since Google Forms™ cannot do that by itself.
What do people see when every slot is full?
A question always needs at least one choice, so SlotKeeper shows one line that you word yourself, such as 'No places left'. It can also close the form for you.
Can one person sign up for several slots?
Yes, with a checkbox question, which needs SlotKeeper Pro. Google Forms™' own response validation can cap how many boxes one person ticks.
What if someone had the form open before a slot filled?
In our tests, Google Forms™ refused the removed choice when that person submitted, and asked them to choose again.
Can each slot have a different number of places?
Yes. The limit is set per choice, so one slot can take 1 person and another 20. Choices left without a limit stay open.