Blank screen means auth completed, the URL is chatgpt.com/?..., document.cookie contains a session token — but the React app shell never rendered. Almost always one of: a JS chunk failed to load, a service worker is serving stale cache, or an extension blocked a script / WebSocket. Open DevTools Console first — the first red error usually points straight at the cause.
Common causes
1. Browser cached a chunk that no longer matches the current build
OpenAI ships a new build, the CDN replaces chunk-abc123.js with chunk-def456.js. Your browser holds the old HTML and requests the old chunk URL — 404, or 200 with mismatched hash.
How to judge: Console shows Loading chunk N failed, ChunkLoadError, or Unexpected token '<' (HTML being parsed as JS).
2. Ad-blocker / privacy extension blocked app scripts
uBlock Origin with certain third-party filterlists blocks *.intercom.io, *.statsig.com, *.cloudflareinsights.com — all of which ChatGPT pings during init. The app waits for timeout before rendering.
How to judge: DevTools → Network → look for requests showing ERR_BLOCKED_BY_CLIENT. Or check Console for net::ERR_BLOCKED_BY_CLIENT.
3. Service worker stuck on an old build
ChatGPT registers a service worker for cache. After a big frontend deploy some users get a split-brain SW — old HTML references new chunk URLs but the SW intercepts and serves a cached 404 stub.
How to judge: DevTools → Application → Service Workers. If status isn’t “activated and is running” or the source date is suspiciously old, this is it.
4. Browser policy or site permission blocks JavaScript
Managed Chrome via group policy adds chatgpt.com to “JavaScript blocked”; or you previously did Settings → Site permissions → Block JavaScript on this site.
How to judge: Click the lock icon left of the URL bar → Site settings → check JavaScript isn’t set to Block.
5. CSP / CORS error (rare but stubborn)
Corporate proxies or some VPN extensions inject their own CSP header tighter than OpenAI’s script-src. Inline scripts the app expects to run get refused.
How to judge: Console shows Refused to execute inline script because it violates the following Content Security Policy directive.
Shortest path to fix
Cheapest first: hard refresh → unregister SW → disable extensions → check permissions.
Step 1: Hard refresh to force chunk re-download
Mac: Cmd + Shift + R
Win: Ctrl + Shift + R or Ctrl + F5If it works briefly then goes white again 30s later — the service worker is re-caching the stale chunk. Continue to Step 2.
Step 2: Unregister the service worker
DevTools (F12) → Application → Service Workers
→ find the chatgpt.com row
→ click Unregister
→ Storage tab → Clear site data → uncheck cookies (otherwise you'll log out)
→ close all chatgpt.com tabs
→ reopenOr nuke from Console:
navigator.serviceWorker.getRegistrations().then(rs => rs.forEach(r => r.unregister()));Step 3: Read the first Console error
F12 → Console → reload page → look at the earliest red error. Map to fix:
| Console error | Cause | Fix |
|---|---|---|
ChunkLoadError / Loading chunk N failed | Chunk cache mismatch | Step 1 + Step 2 |
net::ERR_BLOCKED_BY_CLIENT | Extension blocked | Step 4 |
Refused to execute inline script | CSP injected | Step 5 |
Failed to register a ServiceWorker | SW install failed | Step 2 |
CORS policy: No 'Access-Control-Allow-Origin' | Proxy rewrote header | Different network, or Step 5 |
Uncaught SyntaxError: Unexpected token '<' | Chunk URL returned HTML 404 | Step 1 + Step 2 |
Step 4: Disable extensions one by one
Open chrome://extensions → toggle off:
- uBlock Origin / AdGuard
- Privacy Badger / Ghostery
- NoScript / uMatrix
- Anything “Cookie AutoDelete” / “Forget Me Not”
Or use Incognito with extensions disabled (Chrome: Cmd/Ctrl + Shift + N). If Incognito works, extensions are the cause. Re-enable in regular window one at a time to find the offender.
Step 5: Check JS permissions and CSP
Lock icon in URL bar → Site settings
→ JavaScript: Allow
→ Cookies: Allow
→ Insecure content: Block (default is fine)If group policy locked it, local toggles do nothing — IT must add chatgpt.com to the JavaScriptAllowedForUrls policy.
Step 6: Try a different browser / profile
Chrome white, try Safari. If Safari also white, could be backend (check status.openai.com — is ChatGPT green?). If Safari works, it’s browser-side; loop through the steps above.
Prevention
- Keep your browser current; old Chrome / Safari lacking modern ES features will fail to parse the chunk outright.
- Add chatgpt.com to your ad-blocker’s allowlist (uBlock: click icon → big power button to pause, or add as trusted).
- Don’t run two ad-blockers at once; their rules collide.
- After a major OpenAI deploy (usually weekday mornings PT), proactively hard-refresh once before resuming work.
- Bookmark chatgpt.com and enter via bookmark, not browser history — avoids loading a stale URL.
Related reading
- ChatGPT cannot open
- ChatGPT stuck on loading
- ChatGPT login loop
- Login works in one browser only
- Session expired repeatedly
Tags: #ChatGPT #ChatGPT account #Troubleshooting #Debug #Blank screen