Prompt Octopus

The platform integrates directly with the OpenAI API via user-provided API keys, ensuring that responses are generated using the user's own account and model preferences. API keys are stored locally in browser cache and can be cleared at any time, keeping user credentials private and under their control.

The side-by-side comparison layout is the core workflow: users can add multiple prompt columns, view their responses together, and systematically evaluate which phrasings produce the best outputs. This visual approach to prompt comparison is significantly faster than testing prompts sequentially in a standard chat interface.

Prompt history is preserved and accessible at any time through the built-in history view, allowing users to revisit and compare past experiments. Keyboard shortcuts accelerate the workflow, with commands for adding columns, adding rows, viewing history, and adjusting the interface layout.

Prompt Octopus is available as a self-hosted option on GitHub, giving technical users full control over their deployment. This open-source accessibility, combined with the use of your own API key rather than platform-managed credits, makes it an appealing choice for developers who want maximum control and transparency over their prompt engineering workflow.