# loupe

> A Claude Code skill that reviews UI and UX against Apple’s Human Interface Guidelines, measures what it can, flags interfaces that look template-made, and proposes fixes and reworks with evidence. iOS, iPadOS, macOS and the web.

- Version: 1.0.0 (released 2026-10-27)
- Licence: MIT, free
- Author: Ashwin Sathian (https://ashwinsathian.com/)
- Source: https://github.com/AshwinSathian/loupe
- Install: `npx skills add AshwinSathian/loupe`
- loupe is an independent project. It is not affiliated with, endorsed by, or sponsored by Apple Inc. Apple, Human Interface Guidelines, Liquid Glass, SF Pro, SF Symbols, iOS, iPadOS and macOS are trademarks of Apple Inc.
- Testing: In a pre-registered blind round, three Claude judges preferred loupe’s review to one the same model wrote without it in 6 of 9 pairs. Both found nearly every planted defect; loupe’s had fewer findings judged wrong or inflated, and no Blockers on a well-built app. The round failed one of its four rules: recall, by half a defect with Haiku.

## Pages

- [Overview](https://loupe.ashwinsathian.com/): What loupe is, a finding under the loupe, the two tags, the method in eight steps, install.
- [Method](https://loupe.ashwinsathian.com/method): Apple first, outside research labelled against Apple, what it measures, the rules quoted from SKILL.md, the rework bar.
- [Cases](https://loupe.ashwinsathian.com/cases): Full reports on three held-out fixtures from three Claude models, next to reviews written without the skill.
- [Testing](https://loupe.ashwinsathian.com/testing): The pre-registered blind round: method, every pair, results and losses.
- [Tools](https://loupe.ashwinsathian.com/tools): A WCAG contrast checker and a bookmarklet that runs loupe’s measurement script on any page.
- [Specimen](https://loupe.ashwinsathian.com/specimen): This site’s own design system, measured, and loupe’s review of the site.
- [FAQ](https://loupe.ashwinsathian.com/faq): Apple affiliation, web apps, measurement, code changes, models, privacy.

## Source files

- [SKILL.md](https://github.com/AshwinSathian/loupe/blob/main/SKILL.md): the skill itself
- [Pre-registration](https://github.com/AshwinSathian/loupe/blob/main/evals/heldout/preregistration.md) and [results](https://github.com/AshwinSathian/loupe/blob/main/evals/heldout/result.md) of the blind round
- [Changelog](https://github.com/AshwinSathian/loupe/blob/main/CHANGELOG.md)

## Full text

- [llms-full.txt](https://loupe.ashwinsathian.com/llms-full.txt): the summary, install, FAQ and SKILL.md in one file