Overview
When using proxy servers to access certain websites or APIs, you may occasionally encounter a TLS (Transport Layer Security) error. TLS errors usually occur during the HTTPS connection process and can interrupt scraping, automation, or API interactions. This article explains what TLS errors are, why they occur when using proxies, and how to prevent or resolve them.
What Is a TLS Error?
A TLS error means that a secure connection between your system and the target website could not be properly established. TLS is the protocol that enables HTTPS, and any failure during this handshake can result in a connection error.
Common TLS-related error messages include:
"SSL: handshake failed"
"TLS connection failed"
"Error: certificate verify failed"
Why Do TLS Errors Occur When Using Proxies?
TLS errors can happen for several reasons when routing traffic through a proxy server:
1. Incompatible or Outdated TLS Versions
Some proxies or tools may use an outdated TLS version that the target website no longer supports.
2. Mismatched or Missing Headers
If the request headers (especially the User-Agent) are incomplete or inconsistent, some websites may refuse the handshake.
3. Improper Proxy Configuration
Incorrectly configured proxy settings in your scraping or automation script can interfere with the TLS handshake process.
4. Certificate Validation Issues
Some tools or environments may block the connection if they cannot verify the SSL certificate used by the destination server.
5. Target Website Blocks
Certain websites actively monitor and block suspicious TLS fingerprint patterns commonly seen in scraping libraries or automation tools.
How to Fix or Avoid TLS Errors
To minimize or eliminate TLS errors, apply the following best practices:
✅ 1. Use Modern TLS-Compatible Tools
Ensure your script or client supports modern TLS versions (TLS 1.2 or TLS 1.3). Most up-to-date libraries and browsers support these by default.
✅ 2. Set Proper Headers
Always include essential headers like User-Agent, Accept, and Accept-Language to avoid incomplete handshakes.
✅ 3. Correct Proxy Configuration
Make sure your proxy is set up properly in your tool or script. For HTTPS connections, use the correct format and ensure support for tunneling via CONNECT requests if needed.
✅ 4. Use Headless Browsers with Stealth Settings
Tools like Puppeteer or Playwright, when configured with stealth plugins, help mimic real browsers and reduce TLS fingerprint mismatches.
Example TLS Error Messages
When to Contact Support
If you continue experiencing TLS errors despite using proper headers and up-to-date tools, please reach out to our support team opening a support ticket. We can help review your proxy setup and verify TLS compatibility.
Summary
| Issue | Solution |
|---|---|
| Outdated TLS version | Use updated libraries and clients |
| Incomplete headers | Add standard browser headers |
| Proxy misconfiguration | Double-check proxy settings |
| Certificate validation error | Disable SSL verification (if safe) |
| TLS fingerprint blocking | Use headless browsers with stealth features |
