We launched 3D Lab Viewer on Hacker News, and it was a great milestone for the project. Here’s the story behind it.

The Origin

I run 3D Lab Bali, a custom 3D printing service. Every day, customers send us 3D files - STL, STEP, OBJ - and we need to review them quickly. Existing tools either require installing software, creating accounts, or uploading to third-party services.

I wanted something simple: drag and drop a file, see it in the browser, share it with a link. That’s it.

The Tech Stack

The viewer is built on Cloudflare’s platform:

  • Cloudflare Pages hosts the SPA and the API (via Pages Functions)
  • Cloudflare D1 (SQLite at the edge) stores user data, share metadata, and view analytics
  • Cloudflare R2 stores the uploaded 3D files, keyed by user and share ID

This keeps everything at the edge - fast globally, no origin server to manage, and costs are reasonable for a free tool.

The frontend handles 3D rendering client-side with support for multiple file formats: STL, OBJ, STEP/STP, 3MF, and GLB. STEP support is particularly important for engineering workflows since it’s the standard interchange format for CAD.

What Makes It Different

There are other online 3D viewers, but here’s what we focused on:

  1. Zero friction - No signup, no install, no plugins. Just drop a file.
  2. Sharing - Upload a model and get a link. Anyone with the link can view the model in their browser.
  3. Measuring - Real measurement tools: point-to-point distance, face measurement, diameter measurement. Not just a pretty viewer but a useful tool.
  4. STEP support - Many online viewers skip STEP files because parsing them is complex. We support them because that’s what engineers actually use.

Building With Claude

An interesting aspect of this project: significant portions of the codebase were built with the assistance of Claude (Anthropic’s AI). This includes both the frontend application and the infrastructure configuration. The web app repo is literally called 3d-viewer-claude.

Using AI as a coding partner on a real project with real users has been a fascinating experience. It’s particularly effective for the kind of “glue code” that connects services - Cloudflare bindings, API routes, auth flows - where the patterns are well-established but the boilerplate is tedious.

The HN Launch

Posting to Hacker News as a Show HN was both exciting and nerve-wracking. The HN crowd is technical, opinionated, and will absolutely find every edge case in your product. But that’s exactly the feedback you want.

What’s Next

The viewer continues to evolve. Recent additions include mobile support, keyboard shortcuts, and better shared file management. There’s more planned, but the core mission stays the same: make it dead simple to view and share 3D models in the browser.

Try it yourself at viewer.3dlab.id.