A guide to creating minimal reproductions for debugging.

🔗 Live site: repro.fyi

A single-page site that teaches developers (especially beginners and "vibe coders") how to create minimal reproductions when debugging. The key insight: making a minimal repro often solves your own bug before you need to ask anyone for help.

Because repro.fyi is easier to remember than sscce.org, and I got tired of explaining the same debugging principles over and over.

This site is designed to be:

• Scannable — Headings, checklists, and expandable sections
• Linkable — Share specific sections like repro.fyi/#no-screenshots
• Friendly — Written for beginners, not gatekeepers

1. The selfish reason to make repros — Isolation IS debugging
2. What makes a good repro — Steps, debug info, one-click sandboxes
3. How to create one — The "bisect" method of stripping code
4. The checklist — Linkable items to share with people who need guidance

• Val Town — Serverless hosting
• Markdown — Content in index.md
• Marked — Markdown → HTML
• Classless CSS — Switchable between Water.css, Pico, Simple.css, MVP.css, Sakura

The site is a Val Town HTTP val:

• main.ts — HTTP handler that renders markdown with CSS framework picker
• index.md — All the content in Markdown

To preview CSS frameworks, add ?css=pico (or water, simple, mvp, sakura, none) to the URL.

• SSCCE — The OG guide (inspired this site)
• The XY Problem — When you're solving the wrong problem
• How to Report Bugs Effectively — Simon Tatham's classic
• Jam.dev — Tool for capturing bug reports with context

Public domain. Copy it, remix it, make it better.

Built with ❤️ on Val Town