Frequently Asked Questions

Answers to common questions about STLViewer — the free browser-based STL and 3MF viewer.

Is STLViewer free to use?

Yes. You can upload, preview, and share STL or 3MF models for free, with or without an account.

Do I need to create an account?

No. Anonymous uploads work out of the box and produce a share link you can send to anyone. An account is only needed to manage your model library, set thumbnails, or delete models later.

What file formats are supported?

STL (both binary and ASCII) and 3MF are supported today. Only the mesh geometry is parsed — we do not read slicer metadata from 3MF.

Are my uploaded models private?

Yes. Only people with the share link can view your model. The share pages are explicitly excluded from our sitemap, and we send noindex directives to search engine crawlers, so shared models cannot be discovered by searching.

How large a file can I upload?

The current limit is enforced on the upload URL and scales with file type. Files that exceed the limit will be rejected at the presign step before any bytes are uploaded.

Can I embed the viewer on my own site?

Not yet. Embed support is on the roadmap — follow the Discord or Telegram channels linked in the footer for updates.

Where are the files stored?

File blobs live on Cloudflare R2 (S3-compatible object storage). Metadata, accounts, and share-link state are stored in a Supabase Postgres database.

How do I delete a model?

Authenticated users can delete their own models from the dashboard. Deletion is queued and removes the file from storage asynchronously. Anonymous uploads expire on a schedule managed by the queue.

Is there a mobile app?

No native mobile app. STLViewer runs in any modern browser — Safari, Chrome, and Firefox on mobile all work.

How can I support the project?

A link to Buy Me a Coffee is in the footer. Reporting bugs on Discord or Telegram also helps a lot.