If Claude won’t open, messages won’t send, or it keeps spinning, most of the time it’s not that your “account is broken,” but rather browser cache, network routing, or service congestion. Below, we break down troubleshooting by the most common error symptoms so you can quickly pinpoint the issue and get back to using it.
Start by looking at the symptoms: How to identify page spinning and conversation load failures
If the Claude page opens but the chat list keeps loading, first suspect local cache or blocked APIs. Start with a hard refresh (Windows: Ctrl+F5; Mac: Cmd+Shift+R), then log out and log back in once. If it still doesn’t work, try a different browser or an incognito/private window; this quickly distinguishes an “account issue” from a “browser environment issue.”
If incognito works but the normal window doesn’t, it’s basically an extension, cookie, or cache conflict. Temporarily disable ad blockers, script managers, and privacy-related extensions, then clear site data and sign back into Claude—this usually restores normal operation.
Message send failures: Handling order for 429 rate limits and 500/503 congestion
If you see 429, it means requests are too frequent or usage is too high in a short time. The fix is simple: pause for a few minutes before sending again, split a long question into two parts, and avoid repeatedly clicking “Regenerate.” If you’re using Claude on multiple devices on the same network, it’s also recommended to stop using one of them to reduce concurrency.
If you encounter 500 or 503, it’s usually server-side fluctuation or route congestion. In this case, repeatedly refreshing is more likely to make it stick; save what you want to send, wait a bit, and try again. Switching networks (e.g., Wi‑Fi to mobile data, or vice versa) often helps bypass an unstable node.
Login loops and not getting past CAPTCHA: Key browser and network points
If Claude sends you back to the login page after you sign in, common causes are third-party cookies being disabled or incorrect local system time. Temporarily turn off the browser setting that blocks third-party cookies, confirm your system time is set to sync automatically, then clear cookies related to Claude and log in again.
If you’re stuck on a CAPTCHA or verification keeps failing, first rule out network blocking: disable suspicious proxy routing rules, DNS acceleration, or filtering features, and try using the system default DNS once. Corporate and campus networks often restrict verification endpoints; testing with a phone hotspot is the most straightforward.
Attachment upload or long-text paste failures: Content and formatting workarounds
If Claude upload fails, first rename the file to English letters or numbers to avoid special symbols; then confirm the file isn’t being used by another program. Pasting long text directly can easily trigger length limits or formatting parsing issues, so send it in segments and convert complex formatting to plain text before pasting.
If you find the same piece of content fails every time you send it, it may contain anomalous characters, extremely long links, or repeated fragments. Paste the content into Notepad first to “clean” it, then go back to Claude and send it—the success rate will improve noticeably.
Still not resolved: How to prepare minimal reproduction steps and help-request info
If Claude keeps acting up, don’t just say “it doesn’t work.” Record the status code you see (e.g., 429/503), how often it happens, your browser version, whether extensions are enabled, your network type, and whether incognito mode works. This turns troubleshooting from guesswork into pinpointing, and also helps you get effective responses faster when you ask customer support or the community for help later.
