---
title: IntersectionObserver.thresholds
slug: Web/API/IntersectionObserver/thresholds
translation_of: Web/API/IntersectionObserver/thresholds
---
<div>{{APIRef("Intersection Observer API")}}{{draft}}{{SeeCompatTable}}</div>

<p>The {{domxref("IntersectionObserver")}} interface's read-only <strong><code>thresholds</code></strong> property returns the list of intersection thresholds that was specified when the observer was instantiated with {{domxref("IntersectionObserver.IntersectionObserver", "IntersectionObserver()")}}. If only one threshold ratio was provided when instanitating the object, this will be an array containing that single value.</p>

<p>See {{SectionOnPage("/en-US/docs/Web/API/Intersection_Observer_API", "Thresholds")}} to learn how thresholds work.</p>

<h2 id="Syntax">Syntax</h2>

<pre class="syntaxbox"><var><code>var <em>thresholds</em> = </code>IntersectionObserver</var>.thresholds;
</pre>

<h3 id="Value">Value</h3>

<p>An array of intersection thresholds, originally specified using the <code>threshold</code> property when instantiating the observer. If only one observer was specified, without being in an array, this value is a one-entry array containing that threshold. Regardless of the order your original <code>threshold</code> array was in, this one is always sorted in numerically increasing order.</p>

<p>If no <code>threshold</code> option was included when <code>IntersectionObserver()</code> was used to instantiate the observer, the value of <code>thresholds</code> is simply <code>[0]</code>.</p>

<div class="note">
<p>Be careful! Although the <code>options</code> object you can specify when creating an {{domxref("IntersectionObserver")}} has a field named {{domxref("IntersectionObserver.threshold", "threshold")}}, this property is called <code>thresholds</code>. Confusing? Yes. If you accidentally use <code>thresholds</code> as the name of the field in your <code>options</code>, the <code>thresholds</code> array will wind up being simply <code>[0.0]</code>, which is likely not what you expect. Debugging chaos may ensue.</p>
</div>

<h2 id="Examples">Examples</h2>

<p>&lt;&lt;&lt;...&gt;&gt;&gt;</p>

<h2 id="Specifications">Specifications</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('IntersectionObserver', '#dom-intersectionobserver-thresholds', 'IntersectionObserver.thresholds')}}</td>
   <td>{{Spec2('IntersectionObserver')}}</td>
   <td>Initial definition</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</h2>

<p>{{Compat("api.IntersectionObserver.thresholds")}}</p>