grafana/k6 · error

element is not an iframe

Error message

element is not an iframe

What it means

ContentFrame() got a successful DescribeNode response but the node has no FrameID — by CDP semantics only iframe/frame elements carry one. k6 reports this as a plain 'element is not an iframe' error: you asked for the content frame of an element that is not a frame container.

Solutions

1. Fix the selector to target the <iframe> element itself: iframe#app, iframe[title="..."], or frame,iframe
2. Verify with a tagName check before stepping in: await el.evaluate((n) => n.tagName) === 'IFRAME'
3. If the app swapped iframes for another mechanism, use page.frame()/waitForFrame on the actual frame URL or name instead
4. For wrapper containers, chain through the iframe: 'div.widget >> iframe >> button'

Example fix

// before
const frame = await page.$('.widget-container').contentFrame();

// after
const frame = await page.$('.widget-container iframe').contentFrame();

const el = await page.$('.widget iframe'); // selector must end at the <iframe>
if ((await el.evaluate((n) => n.tagName)) !== 'IFRAME') {
  throw new Error('selector did not resolve to an iframe element');
}

async function contentFrameOf(page, selector) {
  const el = await page.$(selector);
  if (!el) return null;
  const isIframe = (await el.evaluate((n) => n.tagName)) === 'IFRAME';
  return isIframe ? await el.contentFrame() : null;
}

try {
  const frame = await el.contentFrame();
} catch (e) {
  if (/element is not an iframe/.test(String(e))) {
    // selector matched a wrapper; descend to the real iframe
    const frame = await (await page.$('.widget iframe')).contentFrame();
  } else throw e;
}

When it happens

Trigger: Calling contentFrame() on a plain element (div, span, ...), or using a frame-chained selector ('iframe >> button') where the prefix before '>>' actually matches a non-iframe node that merely wraps the real iframe; also elements inside the iframe itself being mistaken for the iframe.

Common situations: Selector matches a wrapper div around the iframe instead of the iframe; template components rendering the iframe inside a custom element; copied selectors from DevTools pointing at a container; refactor replaced the iframe with a portal/div.

Related errors

• finding iframe with selector
• getting iframe frame
• an error occurred communicating with k6 Cloud
• " " does not support " " matcher
• can't query n-th element in a chained selector with capture

AI-assisted analysis of grafana/k6@3fcf5388d7 (2026-08-18). Data as JSON: /api/errors/979f5ca587e6844e. Report an issue: GitHub.

Appendix: source

Thrown at internal/js/modules/k6/browser/common/element_handle.go:862

		return fmt.Errorf("clicking on element: %w", err)
	}
	applySlowMo(h.ctx)

	return nil
}

// ContentFrame returns the frame that contains this element.
func (h *ElementHandle) ContentFrame() (*Frame, error) {
	var (
		node *cdp.Node
		err  error
	)
	action := dom.DescribeNode().WithObjectID(h.remoteObject.ObjectID)
	if node, err = action.Do(cdp.WithExecutor(h.ctx, h.session)); err != nil {
		return nil, fmt.Errorf("getting remote node %q: %w", h.remoteObject.ObjectID, err)
	}
	if node == nil || node.FrameID == "" {
		return nil, fmt.Errorf("element is not an iframe")
	}

	frame, ok := h.frame.manager.getFrameByID(node.FrameID)
	if !ok {
		return nil, fmt.Errorf("frame not found for id %s", node.FrameID)
	}

	return frame, nil
}

// Dblclick scrolls element into view and double clicks on the element.
func (h *ElementHandle) Dblclick(opts *ElementHandleDblclickOptions) error {
	dblclick := func(_ context.Context, handle *ElementHandle, p *Position) (any, error) {
		return nil, handle.dblclick(p, opts.ToMouseClickOptions())
	}
	dblclickAction := h.newPointerAction(dblclick, &opts.ElementHandleBasePointerOptions)
	if _, err := call(h.ctx, dblclickAction, opts.Timeout); err != nil {
		return fmt.Errorf("double clicking on element: %w", err)

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