Can you sign an STL file to prove you made it?

Yes. SliceFoundry Byte Sign embeds an Ed25519 cryptographic signature at the end of an STL. Anyone can upload the file later and verify the signature matches the creator's public key.

Does signing an STL break my slicer?

No. The signature is appended after the mesh data as extra bytes. Standard slicers read the triangle data and ignore the trailing signature block.

How do I verify an STL signature?

Open Byte Sign in SliceFoundry, switch to Verify, and upload the STL. The tool reports whether a valid signature is present and which creator profile signed it.

Byte Sign - Cryptographically Sign and Verify STL Files in Your Browser

Byte Sign lets you cryptographically sign an STL before you upload it to a marketplace, send it to a client, or post it in a community. SliceFoundry embeds an Ed25519 byte signature at the end of the file - invisible to slicers, but verifiable by anyone with the signed download. Prove authorship, catch unauthorized re-uploads, and show buyers they got the file from the original creator.

Signing happens in your browser. Your private key stays in your SliceFoundry account (or you create a named signature profile with its own key pair). Verification is just as fast: upload any STL and Byte Sign tells you whether a valid signature is present, who signed it, and when.

Why Sign an STL?

Prove you made it. When someone re-hosts your mesh without credit, a signed copy is evidence you published first.
Build buyer trust. Patreon tiers, Etsy listings, and commission clients can verify they received an authentic file.
Track your releases. Different signature profiles for Patreon vs. commercial vs. personal drops.
Community moderation. Moderators can quickly check whether a disputed upload matches a known creator's key.
Compatible verification. Signatures use a documented byte block format also recognized by Draftr.

How Byte Sign Works

Create a signature profile. SliceFoundry generates an Ed25519 key pair and stores it in your account. Set a display name and optional icon.
Upload your STL. Pick the mesh you are about to share - commissions, free releases, paid packs, or one-off exports from SliceFoundry.
Sign and download. The signature is appended after the triangle data. Your slicer ignores the extra bytes; verifiers read them.
Verify anytime. You or anyone else can upload the file later and confirm the signature matches the claimed creator.

Sign vs. Verify

Use Sign when you are the author publishing a file. Use Verify when you received an STL and want to check whether it carries a valid signature - for example before paying for a "exclusive" model or when investigating a stolen upload.

Protect 3D models from theft - why creators sign before sharing
AI Printable Model Generator - design, then sign before release
Remix STL - iterate on meshes you own, then re-sign your export

Sign or Verify an STL

Open SliceFoundry Byte Sign

Prefer Hands-On CAD? Try Draftr

When you'd rather design a part precisely by hand than generate it from a prompt, Draftr is a desktop CAD application for Windows and macOS that combines AI with organic parametric CAD in an IDE-like workspace. It pairs a full parametric toolset - sketches, pads, pockets, fillets, chamfers, patterns, and threads - with natural-language AI commands, then exports print-ready STL files (and supports STEP-oriented CAD workflows). It's the natural next step once you outgrow prompt-based generation and want precise, editable, parametric models. Learn more at draftrcad.com.