---
title: TestingBot Tunnel Changelog
description: View the complete version history and release notes for TestingBot Tunnel,
  including new features, improvements, and bug fixes.
source_url:
  html: https://testingbot.com/support/tunnel/changelog
  md: https://testingbot.com/support/tunnel/changelog.md
---

# Release history

Every released version of TestingBot Tunnel, newest first. New features, improvements and bug fixes.

1. ## v4.8
May 2026 Current

  - Added a Prometheus `/metrics` endpoint exposing HTTP request rate, duration and size histograms, HTTPS CONNECT counters, SSH tunnel state and reconnects, active connections, error counters and JVM/process metrics
  - Added `--metrics-auth user:password` to protect the metrics endpoint with HTTP Basic Authentication
  - Added `TESTINGBOT_AUTH`, `TESTINGBOT_PROXY_USERPWD` and `TESTINGBOT_METRICS_AUTH` environment variables so credentials stay out of the process list
  - Sensitive headers are now stripped from debug logging
  - Improved basic authentication handling and logging
  - Updated dependencies

2. ## v4.7
March 2026

  - Fixed an issue with WebSocket proxying

3. ## v4.6
January 2026

  - Fixed an issue with `--debug`

4. ## v4.5
January 2026

  - Added `-s`, `--shared` to share a tunnel with colleagues on your team. Tunnels are not shared by default
  - Updated dependencies
  - Code improvements

5. ## v4.4
October 2025

  - Improved `--proxy` and `--proxy-userpwd` reliability
  - Updated dependencies

6. ## v4.3
August 2025

  - Enhanced `--doctor` diagnostic checks
  - Improved connection monitoring and automatic retry mechanisms
  - Updated Jetty and SSH libraries
  - Dropped support for Java 8 (Java 11+ now required)

7. ## v4.0
December 2024

  - Added WebSocket and Server-Sent Events (SSE) support
  - Added `--nobump` option to disable SSL bumping
  - Upgraded to Jetty 11

8. ## v3.5
May 2023

  - Upgraded secure connection ciphers for improved security
  - Updated dependencies

9. ## v3.2
February 2021

  - Updated dependencies for security and compatibility

10. ## v3.1
February 2020

  - Fixed tunnel polling to prevent indefinite connection attempts
  - Built with Java 8 for broader compatibility
  - Internal code improvements

11. ## v3.0
September 2019

  - Updated Jetty dependencies
  - Various stability improvements

12. ## v2.9
January 2019

  - Various minor fixes to timeout handling and `--doctor` checks

13. ## v2.8
June 2018

  - Fixed null pointer exception in connection handler

14. ## v2.7
June 2018

  - Added upstream HTTPS proxy support via CONNECT method (`--proxy`)
  - Renamed `--jettyport` option to `--localport`
  - Enabled `--nocache` integration with Manual Testing API
  - Removed hardcoded port restrictions

15. ## v2.6
April 2018

  - Added option to inject custom HTTP headers into requests
  - Added automatic basic authentication for configured hosts
  - Clarified `--nocache` behavior: disables all HTTP request caching
  - Removed deprecated `--boost` and `--ssl` options
  - Fixed incorrect Java version detection

16. ## v2.5
September 2017

  - The tunnel now reports its version to TestingBot
  - Added `--pac` option to configure a PAC (Proxy Auto-Config) URL for test sessions

17. ## v2.4
August 2017

  - Added `--tunnel-identifier` to run multiple tunnels on the same account
  - Added local directory serving for static file testing
  - Added embedded REST API for tunnel statistics (default port 8003)
  - Improved logging with configurable output format, file logging, and debug levels
  - Improved connection error handling with automatic reconnection

18. ## v2.3
October 2016

  - Added `--doctor` command to troubleshoot configuration issues
  - Debug mode now outputs HTTP headers for easier troubleshooting

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