Why We Built Measurably Privacy-First

Your AI prompts contain some of the most sensitive information in your workflow: proprietary code, business logic, customer data references, and strategic thinking. Any tool that wants to analyze your prompts needs to handle that data with extreme care.

We chose the most aggressive approach: your raw prompts never leave your device.

How It Works

When you type a prompt in ChatGPT, Claude, or any supported tool, the Measurably Chrome extension:

1. Captures the prompt text in the browser tab 2. Scores it locally using our heuristic engine (runs in ~2ms) 3. Displays your score in a non-intrusive badge 4. Syncs only numeric scores and metadata to the cloud

Step 4 sends data like: { score: 72, dimensions: { specificity: 85, context: 68, ... }, tool: "claude", timestamp: "..." }

It does not send: your prompt text, any code you pasted, any error messages, or any response text.

Why Not Use AI to Score?

We could get more nuanced scores by sending prompts to an AI model for analysis. We deliberately chose not to for three reasons:

1. Privacy: Sending prompts to another AI service defeats the purpose 2. Speed: Heuristic scoring runs in <2ms; API calls take 500ms+ 3. Cost: On-device scoring is free; API calls add up fast

Our heuristic engine isn't perfect — it can't understand semantic meaning the way an LLM can. But it captures the structural and syntactic patterns that correlate most strongly with prompt quality, and it does so without any privacy tradeoff.

What Data Reaches the Cloud

Numeric dimension scores (6 numbers, each 0-100)

Overall AES score (1 number)

Which tool was used (e.g., "chatgpt", "claude")

Prompt length in characters and estimated tokens

Timestamp

That's it. This data powers your dashboard trends, weekly digests, and coaching recommendations — without us ever seeing a single word you typed.

Verification

The extension is open-source. You can inspect every line of the content scripts, background service worker, and scoring engine at github.com/ashlrai/prompt-trackr.