Browser close reasons

A browser session may close for a variety of reasons, including normal completion, inactivity, connection errors, or errors in the headless browser instance. As a best practice, wrap puppeteer.connect or puppeteer.launch in a try...catch ↗ statement to handle unexpected closures gracefully.

To find the reason that a browser closed:

1. In the Cloudflare dashboard, go to the Browser Run page.

   Go to Browser Run

2. Select the Runs tab.

Browser Run sessions are billed based on usage. We do not charge for sessions that error due to underlying Browser Run infrastructure.

Close reasons

Reason	Description
Normal closure	Your code called browser.close() and the session ended normally. No action needed.
Browser idle	The session received no commands for the configured inactivity timeout (60 seconds by default, up to 10 minutes with keep_alive). To prevent idle closures, send commands within the inactivity window or increase the keep_alive value.
Chromium crashed	The Chromium instance inside the session crashed, often because the page consumed too much memory (large DOMs, heavy JavaScript, or many concurrent pages). Try reducing page complexity, closing unused pages, or breaking work into smaller tasks.
Connection error	The connection between the client and Browser Run was interrupted. This can be caused by network issues, your Worker reaching its CPU time limit, or a WebSocket disconnection. Retry the operation with a try...catch block.
Session evicted	Browser Run recycled the session due to infrastructure maintenance or a new release deployment. This is not caused by your code. Retry the operation with a try...catch block and reconnection logic.

Handling unexpected closures

Sessions can close at any time due to infrastructure events, network issues, or browser crashes. Design your code to handle these cases by wrapping browser operations in a try...catch block and reconnecting when needed.

JavaScript

async function runBrowser(env) {
  let browser;
  try {
    browser = await puppeteer.launch(env.MYBROWSER);
    const page = await browser.newPage();
    await page.goto("https://example.com");
    // Your browser automation logic
  } catch (error) {
    console.error("Browser session ended unexpectedly:", error.message);
    // Retry or return an error response
  } finally {
    await browser?.close();
  }
}

Explain Code

For long-running or critical workflows, consider adding retry logic:

JavaScript

async function runWithRetry(env, maxRetries = 3) {
  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    try {
      return await runBrowser(env);
    } catch (error) {
      if (attempt === maxRetries) throw error;
      console.log(`Attempt ${attempt} failed, retrying...`);
    }
  }
}

Explain Code