Arkpine SoftwareGuides · Updated November 2026
SlotKeeper
Limit responses per option in Google Forms™
Google Forms™ has no built-in setting that caps how many people can pick one choice. You can watch the counts in a linked sheet and delete a full choice by hand, or let an add-on do it: SlotKeeper recounts after every response and removes a choice from the form once it reaches its limit.
Free for one limited question per form, with any number of choices and responses. Pro from $29.99 a year.
What Google Forms™ can limit by itself
Google Forms™ has a few limits built in. None of them caps a single choice:
- Limit to 1 response (Settings, Responses) allows one response per Google account. Respondents must sign in to Google. It limits people, not choices.
- Response validation on a checkbox question can require at least, at most or exactly a number of ticks. That limits how many boxes one person ticks, not how many people pick a box.
- Accepting responses (the switch on the Responses tab) closes the whole form, not one choice.
Menu names here are as of November 2026; Google moves them now and then.
Doing it by hand
- Link a sheet
On the form's Responses tab, link the form to a Google Sheets™ spreadsheet. Each response becomes a row, and each question a column.
- Count each choice
Next to the responses, count one choice per cell, for example
=COUNTIF('Form Responses 1'!C:C, "Monday 9:00"). Use your own tab name, column and choice text. - Remove the full one
When a count reaches its limit, open the form, edit the question and delete that choice. Add it back if a place frees up.
Where the manual way falls short
- Someone has to be watching. Between the response that fills a choice and your edit, anyone can still pick it, and a busy sign-up fills while you are away.
- Checkbox answers share one cell. All ticked choices land in one cell separated by commas, so count them with a wildcard, such as
"*Monday 9:00*", and pick choice texts that are not part of each other. - Freed places stay hidden. If you delete a response, nothing puts the choice back unless you do.
If you write code, an Apps Script trigger that runs on each form submission can recount and rewrite the choices. That is the approach SlotKeeper takes, packaged as an add-on with a settings panel.
With SlotKeeper
- Open it in your form
Start SlotKeeper from the add-ons menu of the form editor.
- Pick the question
Tick a multiple-choice or dropdown question. Checkbox questions need Pro.
- Type the limits
Type a limit next to each choice you want to cap, leave the others empty, and press Save.
What happens after that
- After each response it recounts from the actual responses in your form, rather than keeping a separate counter, so a count cannot drift. Submissions that arrive together are handled one at a time.
- A full choice is removed a few seconds after the response that fills it.
- When every limited choice is full, the question shows one line you word yourself, such as "No places left", and the form can close itself.
- Failures are not silent. Google sends no email when an add-on's automatic update fails, so SlotKeeper emails you and shows it at the top of its panel.
Free and Pro
Free: one limited multiple-choice or dropdown question per form, any number of choices and responses, no time limit and no sign-up. Removing and restoring choices, closing the form and the alerts are all free.
Pro, $29.99 a year or $79 lifetime: any number of limited questions, limits on checkbox questions, places left in the choice text such as "Monday 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. Two people who submit within the seconds before a choice is removed can both take the last place. SlotKeeper cannot prevent this; it lists the late answers by time in its panel and emails you.
- A page opened earlier. In our tests, someone who had the form open before a choice filled and then submitted it was asked by Google Forms™ to choose again.
- Deleted responses free a place later, not at once: 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. The panel says so when you reach it.
Questions
Can Google Forms™ limit responses per option without an add-on?
Not on its own. Google Forms™ has no setting that caps a single choice, so you either remove a full choice by hand or use an add-on that does it after each response.
Is SlotKeeper free?
Free for one limited multiple-choice or dropdown question per form, with any number of choices and responses and no time limit. Pro adds more limited questions, checkbox questions, places left in the choice text and a total response limit, for $29.99 a year or $79 lifetime.
Can two people still get the last place?
Yes, if both submit within the few seconds before the choice is removed. SlotKeeper cannot prevent that, but it lists the late answers by time in its panel and emails you.
What happens when I delete a response?
The place comes back at the next submission, at the hourly check, or when you open the SlotKeeper panel. Google Forms™ has no event for a deleted response, so it is not instant.
Can respondents see how many places are left?
With Pro, yes: the choice text can show the places left, such as 'Monday 9:00 (3 left)'.