Sell STL Files Online —
Keep 100% of Every Sale
Proofly is the only 3D model marketplace that charges 0% commission. Upload your STL files, set your price, and every dollar goes directly to you. Buyers pay a flat $1 platform fee — you keep everything else. Every download is automatically watermarked so you can trace piracy back to the source.
How much do you keep per sale?
Commission rates vary widely across STL marketplaces. On a $10 STL sale, here is what you actually receive after each platform takes its cut:
| Platform | Commission | You keep on $10 sale |
|---|---|---|
| Proofly | 0% | $10.00 |
| CGTrader | 30–35% | $6.50–$7.00 |
| Cults3D | 20% | $8.00 |
| MyMiniFactory | 15–30% | $7.00–$8.50 |
| Printables | not for sale | free only |
| Patreon | 8–12% + fees | $8.00–$9.00 |
| Gumroad | 10% | $9.00 |
* Stripe processing fee (~2.9% + $0.30) applies on all platforms. Proofly charges no platform commission on top of this. Rates correct as of 2026; check each platform for current terms.
Why 3D printing designers sell STL files on Proofly
0% commission — your price is your revenue
Every other major STL marketplace takes 15–35% of your sale. Proofly takes nothing. Buyers pay a flat $1 fee per order — that funds the platform. You keep 100% of whatever you charge. Price a miniature pack at $12 and you receive $12 (minus Stripe processing).
HiddenMark watermarking — trace every leaked file
STL piracy is rampant. Files shared on Telegram groups, Discord servers, and "free STL" sites cost 3D printing designers significant income. Proofly embeds an invisible HiddenMark code into the mesh of every download — unique per buyer. If your file appears somewhere it shouldn't, upload it to the verifier and instantly identify which purchase was leaked. One-click DMCA certificate included.
In-browser 3D viewer — convert browsers into buyers
Buyers can rotate, zoom, and inspect your STL directly in their browser before purchasing — no download required. The viewer shows polygon count, bounding box dimensions (in mm for printing), and a watertight check. Buyers know exactly what they're getting, which reduces disputes and increases purchase confidence.
AI-generated listing copy — publish faster
Click "Generate description" and Claude AI writes your listing title, description, tags, and suggested price based on your file name and category. It also generates an automatic translation in 20 languages so international buyers find your STL in their language. Cut listing time from 15 minutes to under 3 minutes.
Sell FDM, resin, and multi-format bundles
Upload STL for FDM printing, pre-supported STL for resin, 3MF (with color and material data), and source files (Fusion 360, Blender) in a single ZIP bundle. Buyers get everything in one purchase. Set one price for the complete package rather than splitting revenue across separate listings.
How to start selling STL files on Proofly
- 1
Create a free account
Sign up at proofly.store/register. No subscription, no upfront fee. Your account is your storefront — customize it with a profile photo, bio, and social links.
- 2
Connect Stripe to receive payments
Go to Dashboard → Earnings → Connect Stripe. It takes about 5 minutes. Stripe handles all payment processing; revenue transfers directly to your connected bank account or debit card.
- 3
Upload your STL files
Drag your STL (or ZIP with multiple formats) into the upload form. The AI description generator fills in your listing copy automatically. Add your price, upload a cover image (or let the 3D viewer generate one), and publish.
- 4
Each download is automatically watermarked
When a buyer purchases and downloads, Proofly embeds a unique HiddenMark code into their copy of the STL. No action required on your part. If the file is later found on a piracy site, you have proof of the exact purchase it came from.
- 5
Get paid automatically
Stripe deposits your earnings on a weekly or monthly schedule (your choice). View your sales, revenue by model, and buyer geography in Dashboard → Analytics.
What STL categories sell best
Based on the 3D printing community, the highest-demand STL categories are:
Frequently asked questions
What percentage do I keep when I sell STL files on Proofly?
You keep 100% of your listed price. Proofly does not take a commission. Buyers pay a flat $1 USD platform fee on top of your price — this covers payment processing and platform costs. For example, if you price an STL at $5.00, you receive $5.00 (minus Stripe's standard processing fee of ~2.9% + $0.30). This compares to CGTrader taking 30–35% or Cults3D taking 20%.
Can I sell STL files made for FDM and resin printing?
Yes. Proofly accepts STL files for all 3D printing methods: FDM (Fused Deposition Modeling) files for printers like Bambu Lab, Prusa, Creality, and Voron builds; MSLA/SLA resin files for Elegoo, Anycubic, and Phrozen printers; and SLS/MJF files for professional printers. You can also sell pre-supported STLs, multi-part assemblies packed in ZIP archives, and companion files (Fusion 360 source, slicer profiles, print instructions).
How are my STL files protected from piracy?
Every download is automatically stamped with HiddenMark — an invisible watermark embedded directly in the mesh geometry of the STL binary header and vertex data. Each buyer receives a uniquely coded copy tied to their purchase. If your STL file appears on a piracy forum or free-download site, upload it to proofly.store/hiddenmark to instantly identify which purchase it originated from. You can then send a DMCA takedown with a verifiable proof-of-authorship certificate.
Do I need exclusivity? Can I sell the same STL on Cults3D, Patreon, and Proofly?
There is no exclusivity requirement on Proofly. You can sell the same STL file on multiple platforms simultaneously — CGTrader, Cults3D, MyMiniFactory, Printables, your own Patreon, and Proofly at the same time. Many designers use Proofly for a premium listing (with multi-format bundle, companion files, and 3D viewer preview) while offering a free or lower-quality version elsewhere to drive traffic.
What file formats beyond STL can I sell?
STL is the most common format for 3D printing, but Proofly also accepts GLB/GLTF (game-ready models), OBJ+MTL (with materials), FBX (rigged characters), 3MF (next-generation print format with color and material data), and BLEND (Blender source files). You can bundle multiple formats in a single ZIP archive — for example, STL + 3MF + Fusion 360 .f3d source — and buyers download the complete package.
How do I get paid for my STL sales?
Connect your Stripe account during onboarding — it takes about 5 minutes. When a buyer completes a purchase, Stripe transfers the sale amount (your price) directly to your connected Stripe account. You can configure automatic weekly or monthly payouts to your bank account or debit card. Proofly never holds your money — revenue goes directly from buyer to your Stripe account via Stripe Connect.
Can I sell pre-supported STL files for resin printing?
Yes. Pre-supported STL files — where supports are already built into the mesh for resin FEP/FDM bed adhesion — are a premium product in the 3D printing community. Upload your pre-supported version as the main STL and optionally include the unsupported version as a bonus file in a ZIP. Buyers using Elegoo, Anycubic, or Phrozen printers especially value pre-supported models because it removes a time-consuming preparation step. Premium pricing ($8–$25) is common for high-quality pre-supported miniature and figurine STLs.
Is there a minimum price for STL files on Proofly?
You can set any price you like, including $0 (free). Many designers use a freemium model: offer a simple STL for free to build followers, then sell premium packs, multi-part assemblies, or pre-supported versions. If you price an STL at $0.00, buyers download it without a payment session — no $1 fee applies for free downloads. The $1 platform fee only applies to paid purchases.
More from Proofly
Game-ready 3D assets with PBR materials and animations — for Unity, Unreal Engine, and Three.js.
Complete guide to all formats — STL, GLB, OBJ, FBX, 3MF, and ZIP bundles.
How HiddenMark mesh watermarking works — trace leaks back to the source purchase.
See live STL listings with in-browser 3D viewer, bounding box dimensions, and watertight check.
Sell by format
Start selling your STL files today
Free account, 0% commission, built-in 3D viewer, automatic piracy tracing. Upload your first STL in under 5 minutes.
No credit card required. Free to list.