What it does
16x Prompt is a desktop application for developers who work with AI on existing codebases. You pick the source files that matter, write the task instructions, and the app assembles them into a single prompt with formatting instructions added. You can paste the finished prompt into ChatGPT, Claude or another chat, or send it directly through an API using your own key. The site names OpenAI, Anthropic, Google Gemini, DeepSeek, OpenRouter, Ollama and Azure OpenAI, plus any provider that follows the OpenAI API format. A code edit feature can apply returned changes with visual diffs and reversible backups, and responses from two models can be compared side by side. The site says prompt assembly runs on your machine and that none of your data is stored on its servers; only calls made with your own API key reach the model providers. Workspaces group several repositories, and saved task instructions and custom instructions can be reused across projects.
Capabilities
- Builds prompts from selected source files, task instructions and formatting instructions
- Copy the prompt, or send it through your own API key to the supported providers
- Code edit feature applies changes with visual diffs and reversible backups
- Side-by-side comparison of responses from different models
- Built-in token limit counter
- Workspaces for several repositories, with saved task and custom instructions
When to use it
- Giving a chat model the right files from a large existing codebase
- Reusing the same refactoring or documentation prompts across projects
- Trying one coding task on several models before choosing one
- Working from an existing ChatGPT Plus or Claude Pro subscription by pasting prompts into the chat window
