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Current version: 1.2.0. See version history.

This plugin displays HTML content and records responses generated by button click. The stimulus can be displayed until a response is given, or for a pre-determined amount of time. The trial can be ended automatically if the participant has failed to respond within a fixed length of time. The button itself can be customized using HTML formatting.


In addition to the parameters available in all plugins, this plugin accepts the following parameters. Parameters with a default value of undefined must be specified. Other parameters can be left unspecified if the default value is acceptable.

Parameter Type Default Value Description
stimulus HTML string undefined The HTML content to be displayed.
choices array of strings [] Labels for the buttons. Each different string in the array will generate a different button.
button_html HTML string '<button class="jspsych-btn">%choice%</button>' A template of HTML for generating the button elements. You can override this to create customized buttons of various kinds. The string %choice% will be changed to the corresponding element of the choices array. You may also specify an array of strings, if you need different HTML to render for each button. If you do specify an array, the choices array and this array must have the same length. The HTML from position 0 in the button_html array will be used to create the button for element 0 in the choices array, and so on.
prompt string null This string can contain HTML markup. Any content here will be displayed below the stimulus. The intention is that it can be used to provide a reminder about the action the participant is supposed to take (e.g., which key to press).
trial_duration numeric null How long to wait for the participant to make a response before ending the trial in milliseconds. If the participant fails to make a response before this timer is reached, the participant's response will be recorded as null for the trial and the trial will end. If the value of this parameter is null, the trial will wait for a response indefinitely.
stimulus_duration numeric null How long to display the stimulus in milliseconds. The visibility CSS property of the stimulus will be set to hidden after this time has elapsed. If this is null, then the stimulus will remain visible until the trial ends.
margin_vertical string '0px' Vertical margin of the button(s).
margin_horizontal string '8px' Horizontal margin of the button(s).
response_ends_trial boolean true If true, then the trial will end whenever the participant makes a response (assuming they make their response before the cutoff specified by the trial_duration parameter). If false, then the trial will continue until the value for trial_duration is reached. You can set this parameter to false to force the participant to view a stimulus for a fixed amount of time, even if they respond before the time is complete.
enable_button_after numeric 0 How long the button will delay enabling in milliseconds.

Data Generated

In addition to the default data collected by all plugins, this plugin collects the following data for each trial.

Name Type Value
rt numeric The response time in milliseconds for the participant to make a response. The time is measured from when the stimulus first appears on the screen until the participant's response.
response numeric Indicates which button the participant pressed. The first button in the choices array is 0, the second is 1, and so on.
stimulus string The HTML content that was displayed on the screen.


Using the CDN-hosted JavaScript file:

<script src=""></script>

Using the JavaScript file downloaded from a GitHub release dist archive:

<script src="jspsych/plugin-html-button-response.js"></script>

Using NPM:

npm install @jspsych/plugin-html-button-response
import htmlButtonResponse from '@jspsych/plugin-html-button-response';


Displaying question until participant gives a response
var trial = {
  type: jsPsychHtmlButtonResponse,
  stimulus: '<p style="font-size:48px; color:red;">GREEN</p>',
  choices: ['Red', 'Green', 'Blue'],
  prompt: "<p>What color is the ink?</p>"

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