Markdown Studio

Markdown Studio is a free, privacy-focused markdown editor built specifically for prompt engineering and AI workflows. It combines a full-featured markdown editor with tools to write, test, and compare prompts across multiple AI models — all running locally in your browser. You get real-time token counting, prompt templates, smart variables, and a Battle Mode that sends the same prompt to OpenAI, Claude, and Gemini simultaneously so you can compare outputs, tokens, and costs side-by-side.

The editor includes features you'd expect from a modern writing tool: live split preview, multi-tab editing, GitHub sync, Mermaid diagrams, LaTeX math, and export to PDF, HTML, JSON, or Markdown. What sets it apart is the prompt engineering toolkit — 24 battle-tested templates, autocomplete for 23 AI-specific prompt tags, and deterministic execution controls like temperature=0 and seed-based consistency. Everything runs client-side; API calls go directly from your browser to the model provider, so Markdown Studio never sees your data. It works offline after the first load and requires no account or email.

Prompt engineers and AI developers will find the most value here — especially those who need to compare model outputs, track token usage, or maintain reproducible prompt workflows. Technical writers who work with markdown and want a clean, fast editor with GitHub integration will also appreciate it. The enterprise features like audit logging, PII sanitization, and snapshot certification make it suitable for teams that need compliance and governance around prompt execution.