<titledata-rh="true">Evaluate JavaScript | Puppeteer</title><metadata-rh="true"name="viewport"content="width=device-width,initial-scale=1"><metadata-rh="true"name="twitter:card"content="summary_large_image"><metadata-rh="true"property="og:url"content="https://pptr.dev/guides/evaluate-javascript"><metadata-rh="true"name="docsearch:language"content="en"><metadata-rh="true"name="docsearch:counter"content="2"><metadata-rh="true"property="og:title"content="Evaluate JavaScript | Puppeteer"><metadata-rh="true"name="description"content="Puppeteer allows evaluating JavaScript functions in the context of the page"><metadata-rh="true"property="og:description"content="Puppeteer allows evaluating JavaScript functions in the context of the page"><linkdata-rh="true"rel="icon"href="/img/favicon.ico"><linkdata-rh="true"rel="canonical"href="https://pptr.dev/guides/evaluate-javascript"><linkdata-rh="true"rel="alternate"href="https://pptr.dev/guides/evaluate-javascript"hreflang="en"><linkdata-rh="true"rel="alternate"href="https://pptr.dev/guides/evaluate-javascript"hreflang="x-default"><linkdata-rh="true"rel="preconnect"href="https://DVKY664LG7-dsn.algolia.net"crossorigin="anonymous"><linkrel="search"type="application/opensearchdescription+xml"title="Puppeteer"href="/opensearch.xml">
referenced by the evaluated function are correct.</p></div></div><h2class="anchor anchorWithStickyNavbar_LWe7"id="return-types">Return types<ahref="#return-types"class="hash-link"aria-label="Direct link to Return types"title="Direct link to Return types"></a></h2><p>The functions you evaluate can return values. If the returned value is of a
in the script context like in the previous example.</p><p>If the script returns an object, Puppeteer serializes it to a JSON and reconstructs it on the script side. This process might not always yield correct results, for example, when you return a DOM node:</p><divclass="language-ts codeBlockContainer_Ckt0 theme-code-block"style="--prism-color:#393A34;--prism-background-color:#f6f8fa"><divclass="codeBlockContent_biex"><pretabindex="0"class="prism-code language-ts codeBlock_bY9V thin-scrollbar"><codeclass="codeBlockLines_e6Vv"><spanclass="token-line"style="color:#393A34"><spanclass="token keyword"style="color:#00009f">const</span><spanclass="token plain"> body </span><spanclass="token operator"style="color:#393A34">=</span><spanclass="token plain"></span><spanclass="token keyword"style="color:#00009f">await</span><spanclass="token plain"> page</span><spanclass="token punctuation"style="color:#393A34">.</span><spanclass="token function"style="color:#d73a49">evaluate</span><spanclass="token punctuation"style="color:#393A34">(</span><spanclass="token punctuation"style="color:#393A34">(</span><spanclass="token punctuation"style="color:#393A34">)</span><spanclass="token plain"></span><spanclass="token operator"style="color:#393A34">=></span><spanclass="token plain"></span><spanclass="token punctuation"style="color:#393A34">{</span><spanclass="token plain"></span><br></span><spanclass="token-line"style="color:#393A34"><spanclass="token plain"></span><spanclass="token keyword"style="color:#00009f">return</span><spanclass="token plain"> document</span><spanclass="token punctuation"style="color:#393A34">.</span><spanclass="token plain">body</span><spanclass="token punctuation"style="color:#393A34">;</span><spanclass="token plain"></span><br></span><spanclass="token-line"style="color:#393A34"><spanclass="token plain"></span><spanclass="token punctuation"style="color:#393A34">}</span><spanclass="token punctuation"style="color:#393A34">)</span><spanclass="token punctuation"style="color:#393A34">;</span><spanclass="token plain"></span><br></span><spanclass="token-line"style="color:#393A34"><spanclass="token plain"></span><spanclass="token builtin">console</span><spanclass="token punctuation"style="color:#393A34">.</span><spanclass="token function"style="color:#d73a49">log</span><spanclass="token punctuation"style="color:#393A34">(</span><spanclass="token plain">body</span><spanclass="token punctuation"style="color:#393A34">)</span><spanclass="token punctuation"style="color:#393A34">;</span><spanclass="token plain"></span><spanclass="token comment"style="color:#999988;font-style:italic">// {}, unexpected!</span><br></span></code></pre><divclass="buttonGroup__atx"><buttontype="button"aria-label="Copy code to clipboard"title="Copy"class="clean-btn"><spanclass="copyButtonIcons_eSgA"aria-hidden="true"><svgviewBox="0 0 24 24"class="copyButtonIcon_y97N"><pathfill="currentColor"d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svgviewBox="0 0 24 24"class="copyButtonSuccessIcon_LjdS"><pathfill="currentColor"d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>To work with the returned objects, Puppeteer offers a way to return objects by reference:</p><divclass="language-ts codeBlockContainer_Ckt0 theme-code-block"style="--prism-color:#393A34;--prism-background-color:#f6f8fa"><divclass="codeBlockContent_biex"><pretabindex="0"class="prism-code language-ts codeBlock_bY9V thin-scrollbar"><codeclass="codeBlockLines_e6Vv"><spanclass="token-line"style="color:#393A34"><spanclass="token keyword"style="color:#00009f">const</span><spanclass="token plain"> body </span><spanclass="token operator"style="color:#393A34">=</span><spanclass="token plain"></span><spanclass="token keyword"style="color:#00009f">await</span><spanclass="token plain"> page</span><spanclass="token punctuation"style="color
