How to solve the "406 not acceptable" error when trying to open Webflow?
TL;DR
- Clear browser cache and cookies, try incognito mode or another browser, and disable extensions that may interfere.
- Check
Acceptheaders in Developer Tools, reset browser settings if needed, flush DNS cache, and test a different network or disable VPN/proxy.
A “406 Not Acceptable” error typically occurs when the server cannot provide a response that matches the criteria defined by the browser’s request headers (such as Accept). In Webflow’s case, this is unusual but can occur due to browser, network, or proxy-related issues.
1. Clear Browser Cache and Cookies
- Go to your browser settings and clear cache and cookies to eliminate corrupted saved data.
- Restart the browser and try accessing Webflow again.
2. Try a Different Browser or Incognito Mode
- Sometimes browser extensions or settings interfere. Open Webflow in incognito/private mode or try another browser like Chrome, Firefox, or Safari.
3. Disable Browser Extensions
- Temporarily disable ad blockers, script blockers, or proxy extensions, which might alter headers or block specific MIME types.
4. Check Accept Headers Using Developer Tools
- Open Developer Tools in your browser (F12 or right-click → Inspect).
- Go to the Network tab, refresh the page, and check the request headers. Look for unusual values in the
Acceptheader (e.g., overly restrictive MIME types). - If present, reset browser settings to default or create a new user profile.
5. Check with Your Network or Proxy
- A corporate firewall, proxy, or VPN could be modifying the request.
- Disable VPN or proxy temporarily or try switching to a different network (like a mobile hotspot) to check if this resolves the issue.
6. Flush Your DNS Cache
- Sometimes stale IP resolutions can cause server mismatches.
- Use
ipconfig /flushdnson Windows orsudo dscacheutil -flushcache; sudo killall -HUP mDNSResponderon macOS in Terminal.
7. Contact Your Hosting Provider or ISP
- If the issue persists across devices and browsers, your internet provider or network administrator may be filtering content improperly.
- Ask them if content-negotiation via headers is being altered or inspect Webflow’s domain traffic.
Summary
The 406 error in Webflow is often caused by browser or proxy misconfigurations that interfere with acceptable content types. Clear your cache, use another browser, check browser extensions or headers, and try a different network to isolate the issue.