Claude may occasionally run into issues such as “Send failed,” “endless loading spinner,” or an unresponsive page. In most cases, the model isn’t broken—it's caused by network routing issues, browser cache problems, or account risk-control triggers. Below is a prioritized self-troubleshooting checklist for Claude; following it usually restores normal operation quickly.
First, do three quick checks: see whether it’s a service-side outage
When Claude keeps failing, refresh the page and start a new chat to rule out a single conversation getting stuck. Then go to Anthropic’s status page (status.anthropic.com) to see whether there are any known incidents or degraded performance. If the status page looks normal but Claude still throws errors, move on to the next step and troubleshoot your local environment.
Network and node issues: the most common culprit behind “can’t send”
Claude is very sensitive to network stability. Network jitter can cause requests to be sent but responses not to return, which shows up as a spinner or “Message failed.” First, switch to a more stable network (for example, from mobile data back to broadband, or vice versa), and avoid frequently switching proxies/nodes within a short time. If your network is blocking or dropping packets, Claude may fail intermittently; in that case, changing DNS or switching networks is often more effective than repeatedly retrying.
Browser-side troubleshooting: cache, extensions, and privacy settings can “collaterally damage” Claude
If the Claude page is behaving abnormally, first log in using an incognito/private window to quickly determine whether the issue is caused by cache or plugins. If it works in incognito, clear site data (cookies/cache) and temporarily disable ad blockers, script managers, and privacy/anti-tracking extensions, then try again. It’s also recommended to turn off “strict” cross-site restrictions or enterprise security plugins, as they may block requests that Claude needs.
Account and risk-control triggers: how to handle 403, 429, and frequent failures
If Claude shows restricted access, a 403 error, or you get a 429 after sending many messages in a short period, it’s usually due to permission or rate-limiting protections being triggered. Don’t keep hammering retry; wait a few minutes before sending again, and reduce the number of open tabs and concurrent requests. If you frequently switch network regions, Claude may also judge the risk as higher—try to keep your login environment stable before using it again.
Attachment and image upload failures: rule out format and file issues first
If uploads fail in Claude, first try a small file to confirm whether the feature works, then come back to the original file. Common issues include files being too large, incompatible formats, or filenames containing special characters. Renaming the file to use English letters/numbers, compressing it, or converting it to a more common PDF/PNG format usually resolves the problem. If the same file repeatedly fails in Claude, export it as a new file and upload again to avoid source-file corruption or encoding anomalies.
