ChatGPT error codes explained

ChatGPT error codes mostly follow standard HTTP status codes. Roughly, 4xx codes (400, 401, 403, 429) point to something on your side — a bad request, an auth problem, a permission/region block, or a rate limit. 5xx codes (500, 502, 503) are OpenAI-side server problems. Cloudflare's 1020 is a network/access block. The fastest way to know which side you're on is to check status.openai.com first.

Check status.openai.com. If OpenAI reports an incident, the error is on their side — wait and retry. If status looks green, the cause is usually local: try a refresh, an incognito window, a different network, or disable your VPN and extensions. As a rule of thumb, 5xx codes and "at capacity" are OpenAI-side, while 4xx codes and 1020 are usually your-side.

A 400 "bad request" generally means the request sent to ChatGPT was malformed or couldn't be processed as sent. In the app this can follow a corrupted session, a stuck conversation, or bad cached data. Try refreshing, starting a new chat, clearing cache/cookies, or an incognito window. On the API, check your request body and parameters.

A 401 "unauthorized" is an authentication problem — your session, login, or API key wasn't accepted. In the web app, sign out and back in, clear cookies, or try incognito. On the API, confirm your API key is valid, active, and sent correctly. Always check status.openai.com in case there's an auth-related incident.

A 403 "forbidden" means access to the resource is not permitted. This can relate to region or permission restrictions, or a blocked request. Try disabling a VPN/proxy or switching network, make sure you're using a supported region, and verify your account has access to what you're requesting. If it persists after the standard fixes, check OpenAI's help pages.

A 429 "too many requests" means you hit a rate limit by sending too many messages in a short time. Wait a few minutes, slow down, and close extra ChatGPT tabs or devices using the same account. On the API, reduce request frequency and use exponential backoff. See the dedicated 429 guide for details.

These are OpenAI-side server errors: 500 is an internal server error, 502 is a bad gateway, and 503 is service unavailable (often shown as "at capacity"). They usually mean the servers are temporarily overloaded or under maintenance. You can't fix them locally — wait, refresh after a pause, and check the status page. Aggressive retrying can make things worse.

Error 1020 is a Cloudflare "access denied" block tied to your IP, VPN/proxy, or network — not a standard OpenAI status code. Fixes are on your side: disable a VPN or proxy, clear ChatGPT cookies, switch network or device, update your browser, and make sure your device date/time are correct. See the dedicated 1020 guide.

Usually no. Most error codes are temporary server issues (5xx), rate limits (429), or local network/browser problems (1020, some 4xx). A 1020 block is about your IP/network, not a ban. If you genuinely can't access your account after the standard fixes, contact OpenAI support.

Use a multi-model workspace like MultipleChat: when ChatGPT throws a 5xx, "at capacity" or other blocking error, you can switch to Claude, Gemini or another model and keep going for free instead of waiting for OpenAI to recover. It also lets you compare answers across models.

Error messages, codes and fixes change over time. Always confirm current behaviour on OpenAI's official pages — status.openai.com for live incidents and help.openai.com for troubleshooting articles. This guide is independent and not operated by OpenAI.