PromptLab

by dhcjfals0715@gmail.com · Workflow & Planning

Manifest V3 Free

View in Chrome Web Store Data as of 15 Oct 2026

Improve AI prompts with rubric v2 A/B scoring — helpfulness, empathy, accuracy, brevity.

Users

0 in 30 days

Rating

0.0 / 5

unchanged in 30 days

Ratings

0 in 30 days

Store rank

#370K

#278K among extensions

Version

1.1

updated 2 Sep 2026

Users

monthly, 2 months

Latest, 15 Oct 2026: 1 usersMove the mouse over the chart for any month

Ratings count

monthly, 2 months

Latest, 15 Oct 2026: 0 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About PromptLab

Improve your AI prompts instantly with data-backed A/B testing. PromptLab watches as you type in ChatGPT or Claude. Click "✦ Improve with PromptLab" and we'll automatically generate 2 improved versions of your prompt, score all three using GPT-4o, and show you the winner — so you always send the best possible prompt. Features: - Works on ChatGPT and Claude - Generates 2 improved prompt versions instantly - A/B tests and scores each version (1–5) on helpfulness / empathy / accuracy / brevity (1–5, 0.5 steps) - Shows you both versions so you can pick your favorite - One-click prompt replacement