Charles v5.1

Charles v5.1 for Mac

Charles is a professional HTTP/HTTPS debugging proxy for developers and QA teams. It sits between your app and the network so you can inspect requests and responses, diagnose API issues, and validate mobile and desktop clients with repeatable, high-signal traffic capture.

Version 5.1 (April 21, 2026) focuses on performance, clearer request inspection, and smoother day-to-day proxy workflows on macOS.

What’s new in Charles 5.1

Major improvements:

• Java 25 upgrade enabling virtual threads for better overall performance
• URL query parameter highlighting for faster reading of complex URLs
• Rendering performance improvements
• Toolbar proxying toggle to switch system proxy settings on/off (where supported)
• zstd content-encoding support

Minor improvements: stop open transactions when recording stops; Map Remote from HTTP/2 to HTTP/1.1; improved CONNECT matching; error log size limits and filtering.

macOS fixes: repair Install Charles Root Certificate in Java VMs; fix excessive mouse-wheel acceleration in tall text views.

Core capabilities (why teams use Charles)

Traffic inspection: browse structured views of requests, repeat calls, and compare sessions.

SSL/TLS debugging: with proper certificate trust and explicit SSL Proxying configuration, Charles can help inspect encrypted traffic for hosts you control or are authorized to test—always follow policy and local law.

Throttling & breakpoints: simulate slow networks and intervene mid-request for edge-case testing.

Official download

• Product: Charles Web Debugging Proxy
• Version: 5.1
• Vendor: XK72 / Charles site
• Latest & docs: charlesproxy.com

Only intercept traffic on systems and accounts you are permitted to debug.