puppeteer/puppeteer · error · Error

Page is not found

Error message

Page is not found

What it means

Thrown inside BrowserContext.newPage() right after the WebDriver BiDi server acknowledges a new browsing context, when that context has not yet been registered in the internal #pages map (the non-null assertion at line 217 is immediately re-checked at 218). It represents an internal state desync between the BiDi event stream and puppeteer's page registry, not a user mistake.

Source

Thrown at packages/puppeteer-core/src/bidi/BrowserContext.ts:219

   */
  getTargetForPage(page: BidiPage): BidiPageTarget | undefined {
    return this.#targets.get(page)?.[0];
  }

  override async newPage(options?: CreatePageOptions): Promise<Page> {
    using _guard = await this.waitForScreenshotOperations();

    const type =
      options?.type === 'window'
        ? Bidi.BrowsingContext.CreateType.Window
        : Bidi.BrowsingContext.CreateType.Tab;

    const context = await this.userContext.createBrowsingContext(type, {
      background: options?.background,
    });
    const page = this.#pages.get(context)!;
    if (!page) {
      throw new Error('Page is not found');
    }
    if (this.#defaultViewport) {
      try {
        await page.setViewport(this.#defaultViewport);
      } catch (error) {
        // Tolerate not supporting `browsingContext.setViewport`. Only log it.
        this.#logger?.(DEBUG_PREFIXES.error)?.(error);
      }
    }
    if (options?.type === 'window' && options?.windowBounds !== undefined) {
      try {
        await this.browser().setWindowBounds(
          context.windowId,
          options.windowBounds,
        );
      } catch (error) {
        // Tolerate not supporting `browser.setClientWindowState`. Only log it.
        this.#logger?.(DEBUG_PREFIXES.error)?.(error);

View on GitHub (pinned to d484e21c17)

Solutions

1. Retry the newPage() call once after the page map has had time to populate; if it reproduces deterministically, file a puppeteer bug — the invariant should hold.
2. Upgrade puppeteer and the browser (Chrome 122+ / a WebDriver BiDi-compliant build) so the contextCreated event is reliably emitted.
3. Serialize concurrent newPage() calls on the same user context to avoid the registration race.

try { return await ctx.newPage(); } catch (e) { if (e instanceof Error && e.message === 'Page is not found') { /* retry once after the event stream catches up */ await new Promise(r => setTimeout(r, 50)); return await ctx.newPage(); } throw e; }

When it happens

Trigger: Calling browserContext.newPage() / browser.newPage() on a BiDi-backed browser where the browsingContext.contextCreated event either did not arrive or was not processed before the synchronous map lookup at line 217-219; or concurrent newPage() calls against the same incognito user context.

Common situations: A browser build that omits or delays the contextCreated event (older/non-conforming WebDriver BiDi implementations); racing context creation before puppeteer has attached its event listeners; concurrent newPage() from multiple coroutines against one BrowserContext.

Related errors

• Execution context was destroyed, most likely because of a na
• Missing target for DevTools page (id = ${devtoolsTargetId})
• Launch aborted
• Error: failed to find element matching selector "${selector}
• Unknown CDP session with id ${id}

AI-assisted analysis of puppeteer/puppeteer@d484e21c17 (2026-08-12). Data as JSON: /api/errors/82f71d571eba4653. Report an issue: GitHub.