Show HN: PromptLab: Run LLM prompts directly inside Google Sheets

I built PromptLab: a simple Google Sheets add-on that lets you use LLMs like GPT4o, Gemini or DeepSeek directly inside a spreadsheet.

I kept running into the same problem: Getting a huge dataset (like keywords, leads, reviews, etc.) and having to copy-paste it row by row into ChatGPT to filter or categorize it. So I built a lightweight function inside Sheets: =TESTPROMPT(input, model)

You can:

Clean up keyword dumps from Google Ads

Classify leads or responses

Rewrite content at scale

Compare different model outputs side by side

Process 1000+ rows in one go (just drag the formula down)

No API keys needed, no Zapier, no browser extensions.

Would love feedback or ideas on other use cases. Happy to answer any technical/product questions too.