Comparison

Prolific vs Koji

Prolific and Koji both land on Depends.

Prolific

Depends

Confidence: Medium

Buy if you're an academic, UX, or AI team needing fast access to vetted human participants and can absorb per-participant costs.

Depends

Confidence: Low

Worth piloting only if you run recurring, high-volume customer interviews and can validate claims on a live demo.

Prolific versus Koji
Compare	Prolific	Koji
Verdict	Depends	Depends
Best for	Academic researchers running online studies	Product and marketing teams running recurring interviews
Who it's not for	Buyers needing guaranteed participant volume . users report study availability swings	Solo founders needing five quick calls
Privacy	No known public vulnerabilities found in the sources reviewed.¹¹	No known public vulnerabilities found in the sources reviewed.¹³
Support quality	No researcher-side support evidence in sources	No support reviews found
Public sentiment	Sentiment skews positive on Trustpilot, while participant-side Reddit threads flag account holds and declining study availability.^⁵	No verifiable user reviews for this exact product surfaced in the sources reviewed.¹⁵
Biggest gotcha	Participant minimum pay is $8/hour . budget accordingly for cheap studies	A defunct same-name link-in-bio 'Koji' still ranks for pricing searches; don't conflate them

Buyers needing guaranteed participant volume . users report study availability swings
Teams requiring public security and compliance docs before purchase
Fixed-budget projects . per-participant pricing plus fees is unpredictable
Tiny studies where recruiting your own panel is enough