How to Fix “Chat.openai.com Has Been Blocked by CORS Policy” Error

Dozens of users, including paid subscribers, have reported facing this issue since April 2024, when ChatGPT suddenly stopped loading properly across browsers, particularly Microsoft Edge and Google Chrome.

“Access to script at ‘https://cdn.oaistatic.com’ from origin ‘https://chat.openai.com’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource,”
you’re not alone.

How to Fix “Chat.openai.com Has Been Blocked by CORS Policy” Error

What Causes the CORS Policy Error?

CORS (Cross-Origin Resource Sharing) is a security mechanism that allows or restricts web applications from requesting resources from a different domain.
When you see this message, it means your browser is being prevented from loading ChatGPT’s scripts due to a misconfiguration or conflict between your browser, cached data, or temporary session files.

Although the OpenAI status page shows no active outages, the CORS policy error typically originates from:

Browser cache or local storage corruption
Conflicts caused by extensions or ad blockers
Temporary bugs in the ChatGPT web app after switching chat modes (e.g., Temporary Chat)
Outdated or corrupted cookies
Browser display width and layout rendering issues

Common Symptoms

Users encountering this issue report:

ChatGPT showing “Hmmm… something seems to have gone wrong” message.
Console errors referencing CORS policy or oaistatic.com.
ChatGPT loading endlessly or displaying a blank page.
Problem persisting across devices or accounts (paid and free).

Common fixes for “Chat.openai.com Has Been Blocked by CORS Policy” Error

1. Clear Browser Data and Re-Login

Go to your browser’s settings.
Clear cache, cookies, and site data for chat.openai.com and chatgpt.com.
Restart the browser and log back in.
Many users reported this fixed the issue temporarily, especially on Chrome and Edge.

2. Reset Browser Local Storage

Open ChatGPT in your browser.
Press F12 to open Developer Tools → go to Application → Local Storage.
Clear all data stored for chat.openai.com.
Refresh the page and sign in again.

3. Resize Your Browser Window

A surprising workaround:

“This bug happens only on wide screen, but if you shrink the window down to a certain width and reload the page, you can use the web version without issue.”

Try reducing your browser width slightly and refresh the page — several users confirmed this fixes the CORS block temporarily.

4. Disable Extensions

Extensions like ad blockers, VPN plugins, or third-party cookies managers can trigger CORS rejections.

Temporarily disable all extensions.
Open a Private or Incognito window.
Log in to ChatGPT again and test if it works.

5. Try Another Browser or Device

Some users noticed the problem appeared only on one browser or one account.
If ChatGPT doesn’t work on Edge, try using Firefox or Chrome, or even the mobile app.

6. Reset Your Browser

One user found success by completely resetting Edge:

“After completely resetting my browser, I was able to use it. After a few minutes it was okay, now again same error. I haven’t clicked on Temporary Chat since.”

To reset Edge or Chrome, go to:
Settings → Reset Settings → Restore settings to their original defaults.

When to Contact OpenAI Support

If none of the steps work, go to the OpenAI Help Center and submit a ticket with:

A screenshot of your browser console error (press F12 → Console tab).
Details about your browser version and operating system.
Your account type (Free or Plus).

This helps the engineering team identify whether it’s an account-specific or system-wide issue.

Final Thoughts

The “Chat.openai.com has been blocked by CORS policy” error is usually a browser-level glitch rather than a server failure.
While inconvenient, most users have resolved it through cache clearing, resizing the browser window, or resetting local storage.

If you rely on ChatGPT for work or study, keeping an alternate browser or mobile app handy is a good way to stay productive while OpenAI addresses these recurring web sync issues.