> ## Documentation Index
> Fetch the complete documentation index at: https://braintrust.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Blank iframe requires console log inspection

export const plans_0 = "Any"

export const deployments_0 = "Braintrust-hosted, Self-hosted"

export const data_plane_version_0 = undefined

export const use_case_0 = "Use case - Any feature using iframe previews in the Braintrust UI"

<Note>
  **Applies to:**

  * Plan - {plans_0}
  * Deployment - {deployments_0}
  * {data_plane_version_0}
  * {use_case_0}
</Note>

## Summary

**Issue:** Iframe previews appear blank in the Braintrust UI with no visible error message. Mixed content errors (HTTP content loaded on HTTPS pages) or other web errors prevent iframes from rendering but are only visible in the browser console.

**Cause:** The UI does not currently surface web errors or iframe loading failures to the user interface.

**Resolution:** Check the browser console for mixed content errors or other web errors that explain why the iframe failed to load.

## Resolution Steps

### Diagnose blank iframe issues

#### Step 1: Open browser developer console

Press `F12` (Windows/Linux) or `Cmd+Option+I` (Mac) to open developer tools.

#### Step 2: Check for mixed content errors

Look for errors containing "Mixed Content" or "blocked loading" in the Console tab. These indicate HTTP resources loaded on an HTTPS page.

#### Step 3: Review other web errors

Check for CORS errors, CSP violations, or network failures that prevent the iframe from loading.

### Fix mixed content errors

#### Step 1: Update resource URLs to HTTPS

Change any HTTP URLs in your iframe source to HTTPS to match the Braintrust page protocol.

#### Step 2: Refresh the page

Reload the Braintrust UI to verify the iframe now displays correctly.