Side by side

HTTP Debugger vs Whistle

Both stand on web debugging proxies. Which one you can start free with, which one lets you read the code, and what each costs once you pay.

HTTP Debugger

Free trial Windows

HTTP Debugger combines broad protocol capture with detailed inspection, traffic modification, replay, and MCP analysis. Its Windows focus and certificate requirement for HTTPS decryption are important setup considerations.

Visit HTTP Debugger

Whistle

Paid AndroidiPhoneLinux+3

Whistle combines traffic capture and editing with desktop, command-line and mobile debugging workflows. Plan for certificate setup for HTTPS and mobile capture, and use a plugin if proxy request permission control is needed.

Visit Whistle

The facts

	HTTP Debugger	Whistle
Free plan	A free trial	Not published
Open source	Not published	Not published
Runs on	Windows	Android, iPhone, Linux, Mac, Web, Windows
Lowest paid plan	See the plans	Not published
Plans published	3	None
Maker	Not published	Not published
Website	httpdebugger.com	wproxy.org
On web debugging proxies	#23 of 27	#27 of 27

HTTP Debugger: what it does well

System-level capture needs no proxy changes
Supports HTTP/1.1, HTTP/2, WebSocket, SSE, and gRPC
Requests can be edited and replayed
MCP server supports Claude Code and Codex
Exports to common data formats

What to know first

Windows-only platform
No free plan
HTTPS decryption requires a trusted root certificate
Purchase includes one year of updates

Whistle: what it does well

Supports HTTP, HTTPS, SOCKS and reverse proxying.
Can replay and edit captured requests.
Inspects WebSocket and TCP data.
Offers graphical desktop and command-line editions.
MIT-licensed and extensible through plugins.

What to know first

HTTPS decryption requires installing its root certificate.
Mobile capture requires proxy setup and certificate trust.
Proxy request permission controls require a plugin.

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