Trowser
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Trowser

Exploratory Tester’s Companion

A real Windows browser for testing, built on 28 years of exploratory testing. Run quicktests, write your own, and let an LLM explore beside you. You stay responsible for what matters.
Freeware with the purpose to enable more and better exploratory testing.

Download for Windows Watch the demo Read the manual (PDF)

Windows 64-bit · WebView2 (Edge) · Free download

Trowser main window: browser, AI Assistant panel, and Script Console with C# quicktests

Humans and machines

Humans are better at judging what is important, separating right from wrong, and dealing with the unknown. Machines are fast at technical detail and slow at exploratory judgment. Trowser is powerful—and still needs a person who understands what might matter.

What you get

Browse and inspect

WebView2 browser with scope and Safe mode, F12 tools, session log, and a record button that turns exploration into a C# script.

C# scripting

Script Console with quicktests for accessibility, performance, security, compatibility, and more—or write your own .csx files.

LLM-ready API

REST and MCP on localhost:6923 so agents can snapshot the page, click by ref, run scans, and report findings while you steer.

LLM usage

Use Chat window for smaller work with your API key (Openouter free is default). For larger sessions, recommendation is to point your agent of choice to the REST API and documentation (use appropriate files from trowserkit folder.) Your prompts steer the work, and your judgment is needed on the results.

MCP: POST http://localhost:6923/mcp

REST: http://localhost:6923 with Authorization: Bearer <api-key>

Start here: API index · llms.txt · in-app manual