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7.99c-.02-.25-.11-.48-.31-.69-.2-.19-.42-.3-.69-.31H6c-.27.02-.48.13-.69.31-.2.2-.3.44-.31.69h1v3c.02.27.11.5.31.69.2.2.42.31.69.31h1c.27 0 .48-.11.69-.31.2-.19.3-.42.31-.69H8V7.98v.01zM7 2.3c-3.14 0-5.7 2.54-5.7 5.68 0 3.14 2.56 5.7 5.7 5.7s5.7-2.55 5.7-5.7c0-3.15-2.56-5.69-5.7-5.69v.01zM7 .98c3.86 0 7 3.14 7 7s-3.14 7-7 7-7-3.12-7-7 3.14-7 7-7z"/></svg></span>note</div><div class=admonitionContent_pbrs><p>Debugging features, such as the Dev Menu, LogBox, and React Native DevTools are disabled in release (production) builds.</div></div> 5<h2 class="anchor anchorWithStickyNavbar_JmGV" id=opening-the-dev-menu>Opening the Dev Menu<a href=#opening-the-dev-menu class=hash-link aria-label="Direct link to Opening the Dev Menu" title="Direct link to Opening the Dev Menu">​</a></h2> 6<p>React Native provides an in-app developer menu providing access to debugging features. You can access the Dev Menu by shaking your device or via keyboard shortcuts:</p> 7<ul> 8<li>iOS Simulator: <kbd>Ctrl</kbd> + <kbd>Cmd ⌘</kbd> + <kbd>Z</kbd> (or Device > Shake)</li> 9<li>Android emulators: <kbd>Cmd ⌘</kbd> + <kbd>M</kbd> (macOS) or <kbd>Ctrl</kbd> + <kbd>M</kbd> (Windows and Linux)</li> 10</ul> 11<p>Alternative (Android): <code>adb shell input keyevent 82</code>.</p> 12<p><img decoding=async loading=lazy alt="The React Native Dev Menu" src=/assets/images/debugging-dev-menu-076-f2f50e00c40ec72dede2d760c174b987.jpg width=1600 height=840 class=img_SS3x></p> 13<h2 class="anchor anchorWithStickyNavbar_JmGV" id=opening-devtools>Opening DevTools<a href=#opening-devtools class=hash-link aria-label="Direct link to Opening DevTools" title="Direct link to Opening DevTools">​</a></h2> 14<p><a href=/docs/react-native-devtools>React Native DevTools</a> is our built-in debugger for React Native. It allows you to inspect and understand how your JavaScript code is running, similar to a web browser.</p> 15<p>To open DevTools, either:</p> 16<ul> 17<li>Select "Open DevTools" in the Dev Menu.</li> 18<li>Press <kbd>j</kbd> from the CLI (<code>npx react-native start</code>).</li> 19</ul> 20<p>On first launch, DevTools will open to a welcome panel, along with an open console drawer where you can view logs and interact with the JavaScript runtime. From the top of the window, you can navigate to other panels, including the integrated React Components Inspector and Profiler.</p> 21<p><img decoding=async loading=lazy alt="React Native DevTools opened to the &amp;quot;Welcome&amp;quot; pane" src=/assets/images/debugging-rndt-welcome-ac9602807bddf2752fc2a73c57028122.jpg width=1600 height=740 class=img_SS3x></p> 22<p>React Native DevTools is powered by a dedicated debugging architecture built into React Native and uses a customized build of the <a href=https://developer.chrome.com/docs/devtools target=_blank rel="noopener noreferrer">Chrome DevTools</a> frontend. This enables us to offer familiar, browser-aligned debugging features that are deeply integrated and built for end-to-end reliability.</p> 23<p>Learn more in our <a href=/docs/react-native-devtools>React Native DevTools guide</a>.</p> 24<div class="theme-admonition theme-admonition-note admonition_WCGJ alert alert--secondary"><div class=admonitionHeading_GCBg><span class=admonitionIcon_L39b><svg viewBox="0 0 14 16"><path fill-rule=evenodd d="M6.3 5.69a.942.942 0 0 1-.28-.7c0-.28.09-.52.28-.7.19-.18.42-.28.7-.28.28 0 .52.09.7.28.18.19.28.42.28.7 0 .28-.09.52-.28.7a1 1 0 0 1-.7.3c-.28 0-.52-.11-.7-.3zM8 7.99c-.02-.25-.11-.48-.31-.69-.2-.19-.42-.3-.69-.31H6c-.27.02-.48.13-.69.31-.2.2-.3.44-.31.69h1v3c.02.27.11.5.31.69.2.2.42.31.69.31h1c.27 0 .48-.11.69-.31.2-.19.3-.42.31-.69H8V7.98v.01zM7 2.3c-3.14 0-5.7 2.54-5.7 5.68 0 3.14 2.56 5.7 5.7 5.7s5.7-2.55 5.7-5.7c0-3.15-2.56-5.69-5.7-5.69v.01zM7 .98c3.86 0 7 3.14 7 7s-3.14 7-7 7-7-3.12-7-7 3.14-7 7-7z"/></svg></span>note</div><div class=admonitionContent_pbrs><p>React Native DevTools is only available with the Hermes engine, and requires either Google Chrome or Microsoft Edge installed.</div></div> 25<div class="theme-admonition theme-admonition-info admonition_WCGJ alert alert--info"><div class=admonitionHeading_GCBg><span class=admonitionIcon_L39b><svg viewBox="0 0 14 16"><path fill-rule=evenodd d="M7 2.3c3.14 0 5.7 2.56 5.7 5.7s-2.56 5.7-5.7 5.7A5.71 5.71 0 0 1 1.3 8c0-3.14 2.56-5.7 5.7-5.7zM7 1C3.14 1 0 4.14 0 8s3.14 7 7 7 7-3.14 7-7-3.14-7-7-7zm1 3H6v5h2V4zm0 6H6v2h2v-2z"/></svg></span>info</div><div class=admonitionContent_pbrs><h4 class="anchor anchorWithStickyNavbar_JmGV" id=flipper-and-alternative-debugging-tools>Flipper and alternative debugging tools<a href=#flipper-and-alternative-debugging-tools class=hash-link aria-label="Direct link to Flipper and alternative debugging tools" title="Direct link to Flipper and alternative debugging tools">​</a></h4><p>React Native DevTools replaces the previous Flipper, Experimental Debugger, and Hermes debugger (Chrome) frontends. If you are on an older version of React Native, please go to the docs <a href=/versions>for your version</a>.<p>For apps using JavaScriptCore instead of Hermes, Direct JSC Debugging is still available (see <a href=/docs/other-debugging-methods>Other Debugging Methods</a>).<p>React Native DevTools is designed for debugging React app concerns, and not to replace native tools. If you want to inspect React Native’s underlying platform layers (for example, while developing a Native Module), please use the debugging tools available in Xcode and Android Studio (see <a href=/docs/next/debugging-native-code>Debugging Native Code</a>).<p>Other useful links:<ul> 26<li> 27<a href=https://shift.infinite.red/why-you-dont-need-flipper-in-your-react-native-app-and-how-to-get-by-without-it-3af461955109 target=_blank>Why you don’t need Flipper in your React Native app … and how to get by without it ↗</a> 28</li> 29</ul></div></div> 30<h2 class="anchor anchorWithStickyNavbar_JmGV" id=logbox>LogBox<a href=#logbox class=hash-link aria-label="Direct link to LogBox" title="Direct link to LogBox">​</a></h2> 31<p>LogBox is an in-app tool that displays when warnings or errors are logged by your app.</p> 32<p><img decoding=async loading=lazy alt="A LogBox warning and an expanded LogBox syntax error" src=/assets/images/debugging-logbox-076-d40ccb710b931f71132ca602b935c0a5.jpg width=1600 height=537 class=img_SS3x></p> 33<h3 class="anchor anchorWithStickyNavbar_JmGV" id=fatal-errors>Fatal Errors<a href=#fatal-errors class=hash-link aria-label="Direct link to Fatal Errors" title="Direct link to Fatal Errors">​</a></h3> 34<p>When an unrecoverable error occurs, such as a JavaScript syntax error, LogBox will open with the location of the error. In this state, LogBox is not dismissable since your code cannot be executed. LogBox will automatically dismiss once the syntax error is fixed — either via Fast Refresh or after a manual reload.</p> 35<h3 class="anchor anchorWithStickyNavbar_JmGV" id=console-errors-and-warnings>Console Errors and Warnings<a href=#console-errors-and-warnings class=hash-link aria-label="Direct link to Console Errors and Warnings" title="Direct link to Console Errors and Warnings">​</a></h3> 36<p>Console errors and warnings are displayed as on-screen notifications with a red or yellow badge.</p> 37<ul> 38<li><strong>Errors</strong> will display with a notification count. Tap the notification to see an expanded view and to paginate through other logs.</li> 39<li><strong>Warnings</strong> will display a notification banner without details, prompting you to open React Native DevTools.</li> 40</ul> 41<p>When React Native DevTools is open, all errors except fatal errors will be hidden to LogBox. We recommend using the Console panel within React Native DevTools as a source of truth, due to various LogBox options which can hide or adjust the level of certain logs.</p> 42<details class="details_IpIu alert alert--info details_jERq" data-collapsed=true><summary><strong>💡 Ignoring logs</strong></summary><div><div class=collapsibleContent_Fd2D><p>LogBox can be configured via the <code>LogBox</code> API.<div class="language-js codeBlockContainer_mQmQ theme-code-block" style=--prism-color:#FFFFFF;--prism-background-color:#282C34><div class=codeBlockTitle_kY6l>js</div><div class=codeBlockContent_t_Hd><pre tabindex=0 class="prism-code language-js codeBlock_RMoD thin-scrollbar" style=color:#FFFFFF;background-color:#282C34><code class=codeBlockLines_AclH><span class=token-line style=color:#FFFFFF><span class="token keyword module" style=color:#c5a5c5>import</span><span class="token plain"> </span><span class="token imports punctuation" style=color:#657b83>{</span><span class="token imports maybe-class-name">LogBox</span><span class="token imports punctuation" style=color:#657b83>}</span><span class="token plain"> </span><span class="token keyword module" style=color:#c5a5c5>from</span><span class="token plain"> </span><span class="token string" style=color:#8dc891>'react-native'</span><span class="token punctuation" style=color:#657b83>;</span><br></span></code></pre></div></div><h4 class="anchor anchorWithStickyNavbar_JmGV" id=ignore-all-logs>Ignore all logs<a href=#ignore-all-logs class=hash-link aria-label="Direct link to Ignore all logs" title="Direct link to Ignore all logs">​</a></h4><p>LogBox notifications can be disabled using <code>LogBox.ignoreAllLogs()</code>. This can be useful in situations such as giving product demos.<div class="language-js codeBlockContainer_mQmQ theme-code-block" style=--prism-color:#FFFFFF;--prism-background-color:#282C34><div class=codeBlockTitle_kY6l>js</div><div class=codeBlockContent_t_Hd><pre tabindex=0 class="prism-code language-js codeBlock_RMoD thin-scrollbar" style=color:#FFFFFF;background-color:#282C34><code class=codeBlockLines_AclH><span class=token-line style=color:#FFFFFF><span class="token maybe-class-name">LogBox</span><span class="token punctuation" style=color:#657b83>.</span><span class="token method function property-access" style=color:#79b6f2>ignoreAllLogs</span><span class="token punctuation" style=color:#657b83>(</span><span class="token punctuation" style=color:#657b83>)</span><span class="token punctuation" style=color:#657b83>;</span><br></span></code></pre></div></div><h4 class="anchor anchorWithStickyNavbar_JmGV" id=ignore-specific-logs>Ignore specific logs<a href=#ignore-specific-logs class=hash-link aria-label="Direct link to Ignore specific logs" title="Direct link to Ignore specific logs">​</a></h4><p>Notifications can be disabled on a per-log basis via <code>LogBox.ignoreLogs()</code>. This can be useful for noisy warnings or those that cannot be fixed, e.g. in a third-party dependency.<div class="language-js codeBlockContainer_mQmQ theme-code-block" style=--prism-color:#FFFFFF;--prism-background-color:#282C34><div class=codeBlockTitle_kY6l>js</div><div class=codeBlockContent_t_Hd><pre tabindex=0 class="prism-code language-js codeBlock_RMoD thin-scrollbar" style=color:#FFFFFF;background-color:#282C34><code class=codeBlockLines_AclH><span class=token-line style=color:#FFFFFF><span class="token maybe-class-name">LogBox</span><span class="token punctuation" style=color:#657b83>.</span><span class="token method function property-access" style=color:#79b6f2>ignoreLogs</span><span class="token punctuation" style=color:#657b83>(</span><span class="token punctuation" style=color:#657b83>[</span><span class="token plain"></span><br></span><span class=token-line style=color:#FFFFFF><span class="token plain"> </span><span class="token comment" style=color:#93a1a1>// Exact message</span><span class="token plain"></span><br></span><span class=token-line style=color:#FFFFFF><span class="token plain"> </span><span class="token string" style=color:#8dc891>'Warning: componentWillReceiveProps has been renamed'</span><span class="token punctuation" style=color:#657b83>,</span><span class="token plain"></span><br></span><span class=token-line style=color:#FFFFFF><span class="token plain" style=display:inline-block></span><br></span><span class=token-line style=color:#FFFFFF><span class="token plain"> </span><span class="token comment" style=color:#93a1a1>// Substring or regex match</span><span class="token plain"></span><br></span><span class=token-line style=color:#FFFFFF><span class="token plain"> </span><span class="token operator" style=color:#fc929e>/</span><span class="token maybe-class-name">GraphQL</span><span class="token plain"> error</span><span class="token operator" style=color:#fc929e>:</span><span class="token plain"> </span><span class="token punctuation" style=color:#657b83>.</span><span class="token operator" style=color:#fc929e>*</span><span class="token operator" style=color:#fc929e>/</span><span class="token punctuation" style=color:#657b83>,</span><span class="token plain"></span><br></span><span class=token-line style=color:#FFFFFF><span class="token plain"></span><span class="token punctuation" style=color:#657b83>]</span><span class="token punctuation" style=color:#657b83>)</span><span class="token punctuation" style=color:#657b83>;</span><br></span></code></pre></div></div><div class="theme-admonition theme-admonition-note admonition_WCGJ alert alert--secondary"><div class=admonitionHeading_GCBg><span class=admonitionIcon_L39b><svg viewBox="0 0 14 16"><path fill-rule=evenodd d="M6.3 5.69a.942.942 0 0 1-.28-.7c0-.28.09-.52.28-.7.19-.18.42-.28.7-.28.28 0 .52.09.7.28.18.19.28.42.28.7 0 .28-.09.52-.28.7a1 1 0 0 1-.7.3c-.28 0-.52-.11-.7-.3zM8 7.99c-.02-.25-.11-.48-.31-.69-.2-.19-.42-.3-.69-.31H6c-.27.02-.48.13-.69.31-.2.2-.3.44-.31.69h1v3c.02.27.11.5.31.69.2.2.42.31.69.31h1c.27 0 .48-.11.69-.31.2-.19.3-.42.31-.69H8V7.98v.01zM7 2.3c-3.14 0-5.7 2.54-5.7 5.68 0 3.14 2.56 5.7 5.7 5.7s5.7-2.55 5.7-5.7c0-3.15-2.56-5.69-5.7-5.69v.01zM7 .98c3.86 0 7 3.14 7 7s-3.14 7-7 7-7-3.12-7-7 3.14-7 7-7z"/></svg></span>note</div><div class=admonitionContent_pbrs><p>LogBox will treat certain errors from React as warnings, which will mean they don't display as an in-app error notification. Advanced users can change this behaviour by customising LogBox's warning filter using <a href=https://github.com/facebook/react-native/blob/d334f4d77eea538dff87fdcf2ebc090246cfdbb0/packages/react-native/Libraries/LogBox/Data/LogBoxData.js#L338 target=_blank rel="noopener noreferrer"><code>LogBoxData.setWarningFilter()</code></a>.</div></div></div></div></details> 43<h2 class="anchor anchorWithStickyNavbar_JmGV" id=performance-monitor>Performance Monitor<a href=#performance-monitor class=hash-link aria-label="Direct link to Performance Monitor" title="Direct link to Performance Monitor">​</a></h2> 44<p>On Android and iOS, an in-app performance overlay can be toggled during development by selecting <strong>"Perf Monitor"</strong> in the Dev Menu. Learn more about this feature <a href=/docs/performance>here</a>.</p> 45<p><img decoding=async loading=lazy alt="The Performance Monitor overlay on iOS and Android" src=/assets/images/debugging-performance-monitor-2968ccaa4d93764fb4791f178f21a16a.jpg width=1600 height=400 class=img_SS3x></p> 46<div class="theme-admonition theme-admonition-info admonition_WCGJ alert alert--info"><div class=admonitionHeading_GCBg><span class=admonitionIcon_L39b><svg viewBox="0 0 14 16"><path fill-rule=evenodd d="M7 2.3c3.14 0 5.7 2.56 5.7 5.7s-2.56 5.7-5.7 5.7A5.71 5.71 0 0 1 1.3 8c0-3.14 2.56-5.7 5.7-5.7zM7 1C3.14 1 0 4.14 0 8s3.14 7 7 7 7-3.14 7-7-3.14-7-7-7zm1 3H6v5h2V4zm0 6H6v2h2v-2z"/></svg></span>info</div><div class=admonitionContent_pbrs><p>The Performance Monitor runs in-app and is a guide. We recommend investigating the native tooling under Android Studio and Xcode for accurate performance measurements.</div></div></div><footer class="theme-doc-footer docusaurus-mt-lg"><div class="theme-doc-footer-edit-meta-row row"><div class=editButtons_t0bR><a href=https://github.com/facebook/react-native-website/edit/main/docs/debugging.md target=_blank rel="noopener noreferrer" class=theme-edit-this-page><svg fill=currentColor height=20 width=20 viewBox="0 0 40 40" class=iconEdit_bHB7 aria-hidden=true><g><path d="m34.5 11.7l-3 3.1-6.3-6.3 3.1-3q0.5-0.5 1.2-0.5t1.1 0.5l3.9 3.9q0.5 0.4 0.5 1.1t-0.5 1.2z m-29.5 17.1l18.4-18.5 6.3 6.3-18.4 18.4h-6.3v-6.2z"/></g></svg>Edit page for next release</a><a href=https://github.com/facebook/react-native-website/edit/main/website/versioned_docs/version-0.79/debugging.md target=_blank rel="noopener noreferrer" class=theme-edit-this-page><svg fill=currentColor height=20 width=20 viewBox="0 0 40 40" class=iconEdit_bHB7 aria-hidden=true><g><path 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