DeepL may suddenly refuse to translate because it flags your traffic as suspicious, revokes API keys, or a corporate firewall blocks the domain. The following sections explain each cause and how to fix it.
Rate‑limiting and IP blocks
When a single IP sends many requests in a short time, DeepL’s Cloudflare protection treats it like a denial‑of‑service attack and blocks the address. VPNs or shared corporate networks can amplify the request volume, triggering a temporary ban. Restarting your router or switching to a different network usually lifts the block.
Revoked API keys and subscription limits
DeepL periodically audits keys that are publicly exposed or used beyond the free quota. If your key is flagged, the service revokes it, stopping all translations until you re‑authenticate and confirm a payment method. Check your account dashboard for any alerts and regenerate a new key if needed.
Corporate firewalls and data‑privacy compliance
Many organizations block external translation services to keep text on internal servers, complying with GDPR or HIPAA. If you are on a corporate network and cannot reach DeepL, contact your IT department to whitelist the domain or use an approved internal tool.
Browser fingerprinting and privacy settings
DeepL inspects browser features such as extensions, canvas rendering, and cookie policies. Privacy‑focused browsers or aggressive ad blockers can trigger the anti‑bot system, causing the site to fail silently. Temporarily disabling extensions or switching to a less restrictive browser can restore access.
Character limits on the free web interface
Non‑registered users are limited to 5,000 characters per translation. Exceeding this limit or repeatedly hitting the button can prompt a temporary lockout. Upgrading to a paid plan removes the restriction and reduces the chance of being flagged.
How to troubleshoot quickly
- Clear browser cache and cookies.
- Disable VPN or use a different network.
- Check your API key status in the account panel.
- Ask IT to whitelist DeepL if on a corporate network.
- Consider upgrading to a paid plan if you need higher limits.