How do I use Prolific's filters?

When you set up a study, you can add filters to make sure the right people see it. We have several hundred to choose from, covering things like:

Want to see the full list? Check out our audience checker, or sign up for a researcher account and start a draft study to browse the options for yourself.

If none of our built-in filters quite hit the mark, you can recruit a custom sample instead.

Most filter answers are self-reported by participants. The main exceptions are age and current country of residence, which we verify and keep up to date automatically. A handful of others, like approval rate, "joined between" dates, and exclusion from other studies, come from participants' actual activity on the platform, not anything they've told us.

Any demographic filters you've applied become available to download as soon as participants start completing your study. Take a look at exporting Prolific demographic data for more.

Screening has to happen through our filters, not inside your study. All eligibility checks need to run through the system described in this article. You can't screen people out once they're already in your study. Read Can I screen participants within my study? to see the exceptions.

English fluency isn't guaranteed by default. Most participants on Prolific are comfortable in English, but if that matters for your study, add an explicit fluent languages filter rather than assuming.

Only two questions are mandatory for participants: age and current country of residence. Every other filter depends on participants having answered that question, so some participants may not be reachable through filters they've left blank.

Participants can't see which filters you've used. They also can't tweak their answers on the fly: they can delete a response, but they'll only be able to re-enter it once any studies they're currently active in have finished.

Selecting multiple options within one filter is automatically OR. For example, choosing English and Polish under fluent languages reaches participants fluent in either. Combining separate filters defaults to AND instead, so participants must match every filter you've added. To switch to OR across different filters, use the AND/OR toggle; this works for up to five filters at a time. AND narrows your pool, OR widens it.

You can check this while setting up your study. In the audience section, select your filters and you'll see a live count of active participants who match. If fewer than five participants qualify, we'll hide the exact number to protect participant privacy.

For more detail, see recruiting participants.

As a rule of thumb, expect a response rate of around 40–50% from your eligible pool.

Got a question we haven't covered? Get in touch with our Support Team using the button at the bottom of the page. We're happy to help you get your filters right.