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Running HTML experiment quick question

Hey everyone,

Doing a dissertation in my final year of psychology undergra, and I’m trying to get a trial version of my experiment to load up in my browser, so I can put it on a webserver and eventually online for the world to use!

OS (e.g. Win10): WIN10
PsychoPy version (e.g. 1.84.x): 185.2
Standard Standalone? (y/n) y
What are you trying to achieve?:
Trying to test my experiment online by running the index.html

What specifically went wrong when you tried that?:
When I load up my experiment in the browser, it seems to load fine except the first window where you can select/input “participant number” and “session number” at the top says "fields with an asterisk (*) are required. In this window, the “ok” button stays greyed out, regardless of what I put into both fields, causing me/anyone to be unable to actually start the experiment.
What am I doing wrong? How can I fix this?

Apologies for the probable silly question!

Kind regards,


Hi guys,

Any help on this? It’s such a silly issue. I’ve tried opening the index.html in multiple browsers but just cannot press the “ok” button to actually start the experiment. This even happens with the pre-made demos when exported to HTML.

Any help would be greatly appreciated…

Thank you so much,


Hi Davy,

The problem is likely to be that you’re trying to open your web page directly in the browser. You need to access your site through a web server. A local server is fine if you’re still at the stage of testing your code. I use MAMP (, which is free and available for both Mac and Windows.