STL to OBJ Converter

Move a printable STL or scan into OBJ geometry for editing in Blender, Maya or ZBrush, with no upload or account.

Your file never leaves this browser. No account, no upload, no limit on how many you convert.

HOW IT WORKS

How to Convert an STL File to OBJ

Convert the existing STL triangles into an editable OBJ container without pretending they are quads.

  1. Open the STL

    Choose a printable model or scan no larger than 100 MB.

    Processed on your device

  2. Check mesh dimensions

    Inspect triangle count, object count and bounding box before export.

    Coordinate values remain equal

  3. Download the OBJ

    Save the same triangle geometry in OBJ form for your modelling application.

    Triangles remain triangles

What People Do With an OBJ Next

OBJ moves a print mesh into software where you can reshape, organise or present it. Each destination starts with the same triangular surface but leads to a different job.

Build Cleaner Retopology

You use the OBJ as a reference while rebuilding the model with deliberate edge flow.

Generate a model from a photo

Sculpt Surface Detail

You bring the mesh into a sculpting application to add folds, wear or fine forms.

OBJ to STL converter

Create UV Layouts

You unwrap the geometry and prepare texture coordinates inside your modelling software.

Describe a model in words

Prepare a Game Asset

You optimise the mesh, add UVs and build materials for use in a game project.

GLB to STL converter

Render Product Images

You place the object in a lit scene and create stills or turntable renders.

3D model converter

Rescale and Kitbash

You resize the mesh, cut it apart and combine selected forms with other models.

FBX to OBJ converter

opolyo-model.glb @ in about two minutes

What Survives STL to OBJ

An STL begins as a flat collection of triangles, and the OBJ keeps that geometric foundation. Moving it into OBJ does not reconstruct the original modelling decisions. Scale numbers remain untouched because both formats leave units undefined. Triangle count, object count and bounding box give you a final check before download.
GeometryColourMaterialsUnitsTopologyFile size

Geometry

The STL surface carries into OBJ without changing its basic shape. Its existing triangles become OBJ face data.

STL file format

the file you have

Opolyo

this page

Editable OBJ container, unchanged triangle topology

INSIDE THE CONVERSION

How STL to OBJ Conversion Builds the Output

The conversion opens the STL triangle stream and expresses that same surface in OBJ syntax. The container changes, while the geometry stays ready for further work.

  1. 01

    Binary and text STL enter the same path

    The loader detects which STL encoding it received and turns either one into the same in memory triangle geometry.

    Once parsing finishes, the exporter works from that geometry rather than from the original byte layout. The source can therefore be compact binary STL or readable text STL without changing the structure of the OBJ result.

  2. 02

    Triangle vertices become OBJ face records

    Each STL facet supplies three positions and a surface normal for the new OBJ.

    The writer lists those positions as OBJ vertices, then connects them with face records. This makes the surface available to modelling software while preserving the same visible triangular shell.

  3. 03

    The conversion keeps the existing topology

    Changing the container does not rebuild edge flow or infer quad faces.

    The OBJ remains a triangle mesh because those are the faces present in the STL. You can select, sculpt or retopologise it in a modelling application, while the paid workspace provides a separate quad topology option when rebuilding is the goal.

  4. 04

    Coordinate numbers remain unscaled

    STL and OBJ declare no unit, so every loaded position is exported without a unit conversion.

    The bounding box shown before download is the reliable checkpoint. Compare it with the size expected by your next application, then choose that application's import unit without a hidden scale factor from this conversion.

SPECIFICATIONS

STL to OBJ Specifications

The free conversion rewrites STL triangles as OBJ geometry while preserving their coordinate values.

Input

Accepts
.stl
Size ceiling
100 MB
Read in
Your browser

Output

Writes
OBJ text
Topology
Triangles
UVs
Not created

Scale and cost

Scale
Carried through
Conversions
Unlimited
Price
Free

BEFORE YOU CONVERT

Why Opolyo, not a typical STL to OBJ converter

This comparison separates straightforward format conversion from the separate work of retopology and UV creation.
Topology
Most tools:Many quick conversions often relabel triangles without explaining that topology remains unchanged.
Opolyo:Opolyo states plainly that the free OBJ remains triangulated.
UV creation
Most tools:Many format handoffs often leave UV requirements for the later editing stage.
Opolyo:The browser tool creates no UVs and leaves unwrapping to modelling software.
Scale
Most tools:Many import pipelines often assign a working unit after reading STL coordinates.
Opolyo:The converter passes coordinate numbers through because neither format declares a unit.
File privacy
Most tools:Many cloud converters upload scans or printable meshes for processing.
Opolyo:Your STL is read and rewritten only inside the browser tab.
Retopology
Most tools:Many conversion workflows often treat quad generation as a separate processing step.
Opolyo:Quad topology is available through the paid /app/convert workspace rather than the free local path.
Use the browser route when triangle OBJ is the required handoff. Choose the paid workspace when the purpose of conversion is to obtain quad topology. The converter at the top of this page does it without an account.

WHAT YOU GET

Models you can spin before you download

Load your STL and verify the dimensions and triangle count before export. The resulting OBJ opens the same triangulated geometry to an editing workflow, without adding UVs or quads.

Pricing

Every credit turns into a model you keep

Billed every month. Cancel anytime.

Start

For your first prints and props

$19.99

USD

Billed monthly

  • 160 credits / month (16 generations)
  • Standard and Ultra PBR textures
  • GLB, STL & OBJ export
  • Built-in format converter
  • Failed generations refunded automatically
  • Commercial license
  • Email support
Get Opolyo

Cancel anytime.

POPULAR

Build

For people who ship models weekly

$39.99

USD

Billed monthly

  • 360 credits / month (36 generations)
  • Standard and Ultra PBR textures
  • GLB, STL & OBJ export
  • Built-in format converter
  • Failed generations refunded automatically
  • Commercial license
  • Email support
Get Opolyo

Cancel anytime.

BEST VALUE

Scale

For studios and print farms

$89.99

USD

Billed monthly

Everything in Build, plus:
  • 900 credits / month (90 generations)
  • Lowest cost per credit
  • Priority email support (24h response)
Get Opolyo

Cancel anytime.

I filled my first map in just one afternoon! That's 24 props already.

Marcus Reed

Built a Game

STL to OBJ Converter FAQ

Question not here? Ask by email.

  • Yes, the converter writes OBJ geometry for applications such as Blender, Maya and ZBrush. The mesh stays triangulated after conversion.

  • The free browser converter does not create quads or perform retopology. Use the quad topology option in the paid /app/convert workspace when that structure is required.

  • No UVs are invented. UV unwrapping remains a separate operation in modelling software.

  • Yes, the STL triangle geometry carries through into OBJ. Coordinate numbers also remain unchanged.

  • Yes. The loader detects either STL encoding and turns it into the same triangle geometry before the OBJ writer runs.

  • Yes. It costs nothing because processing occurs on your computer rather than on paid compute.

  • Yes, there is no sign in requirement. The converter opens directly in the browser.

  • You can convert an unlimited number of files, each up to 100 MB. The size boundary exists because a larger mesh can exhaust the memory available to the tab.

  • No. The source remains on your device while three.js processes it in the browser.

  • No remote upload occurs. The tab reads the file and prepares the OBJ locally.

  • Yes. The converter displays the triangle count, object count and bounding box it detected before you download.

  • No, STL stores no materials, textures or colour. There is no source material information for the OBJ conversion to recover.

  • STL declares no unit, and OBJ declares none either. The original numerical coordinates pass through without scaling.

  • Disconnected shells remain part of the exported geometry. STL provides no object names for the converter to recover, so the OBJ starts as one loaded mesh containing those separate surfaces.

  • The browser conversion does not simplify the mesh. It expresses the existing STL triangles as OBJ faces, and the triangle count shown before export lets you judge whether the mesh is suitable for editing.

  • The paid Opolyo generator can build a 3D model from one photo or a text description using GPUs. It costs credits, while converting your existing STL into a triangle OBJ in the browser is free.

What people make with Opolyo

5,873 makers and counting. A few of them told us what they made, and what happened next.

  • The customer's payment dashboard, a net revenue panel reading $2,605.00 with $0.00 for the comparison period
    I’m a game dev and originally started using this to turn some of my reference images into 3D assets for a project. A few of the models turned out better than I expected, so I cleaned them up and started selling them on the side too. Just crossed $2,600 in net revenue from those 3D models. Never really planned on becoming an asset seller, but I’m definitely not complaining 🙌
    N
    Nathan Brooks
  • Didn’t think a single image would get me this far. The model needed a little cleanup, but I had a solid base ready in minutes. Saved me an entire afternoon.
    D
    Dylan Reeves
  • Turned one of my kid’s drawings into a little 3D character with Opolyo. She absolutely lost it when she saw it. Probably the most fun thing I’ve made with this so far.
    K
    Kyle Brandt
  • The customer's Stripe gross volume: £231.05 for Sep 2025 to Aug 2026 against £0.00 for the twelve months before, the line flat at zero until a single month of £186.15 near the end
    Honestly didn’t expect anyone to actually pay for the 3D stuff I was making. Put a few of them up for sale just to test it and somehow made £231 from my models. Still feels a bit unreal seeing that number 😂
    O
    Owen Whitaker
  • The customer's Dodo Payments record of paid 3D requests, at a range of different amounts
    I started using Opolyo for a few custom 3D requests from clients and somehow it turned into a little side service of its own. Some people just need a quick conversion, others want more detailed work, so the order sizes are all over the place. Seeing multiple paid requests come in on the same day still feels pretty surreal. Never thought image-to-3D would become something clients actually kept coming back for.
    A
    Adam Pike
  • I use a lot of reference images when working on interior concepts, and this made it really easy to turn an object I liked into a rough 3D asset. I still adjusted a few things afterward, but it saved me from modeling the whole thing from zero.
    C
    Claire Bennett
  • Couldn’t find the exact prop I needed anywhere, so I threw the reference image into Opolyo as a last resort. The first result wasn’t perfect, but the overall shape and proportions were already there. It actually looked like the thing in my reference. After a little cleanup, it was exactly what I needed.
    J
    Jonah Reyes
  • Used it to turn a couple of product images into 3D models for our store. Took a few tries to get the best result, but still much easier than hiring someone to model everything manually.
    G
    Grant Miller
  • The customer's inbox of Stripe payment notifications: five payments, four of $14.99 and one of $125.88
    Woke up, checked my inbox and Stripe notifications just kept showing up. Most were $14.99 orders, then a $125.88 payment landed later in the day. I’m still pretty new to selling my 3D stuff, so seeing 5 sales come in on the same day was a really nice feeling. 🔥
    M
    Miles Prescott
  • I had a photo of a small figurine from years ago that I couldn’t find anywhere anymore. Tried putting it into Opolyo just to see what would happen, and the result was honestly better than I expected. It felt like bringing an old thing back to life. I still want to clean up a few details before printing it, but this is probably my favorite use so far.
    R
    Riley Fenn
  • Turned a photo into a little 3D model, printed it, and gave it to a friend for his birthday. Wasn’t expecting him to react that much 😂 He absolutely loved it. Now I’m thinking of making a few more for Christmas.
    T
    Tyler Hodge
  • The customer's Dodo Payments dashboard for their 3D commission work, totalling $181.92
    I mostly got into this because I like 3D printing and wanted to make a few custom pieces without learning modeling from scratch. Then a couple of people asked if I could make something for them too, so I started taking small requests here and there. Just hit $181.92 from custom 3D commissions. It’s not a huge number, but getting paid for something I was already doing for fun feels pretty awesome.
    W
    Wes Delaney
  • Been playing around with this for a small game project and some of the results are actually really fun. I generated a few props from reference images and one of them ended up fitting the scene perfectly. It’s staying in the game.
    E
    Evan Ross
Other converters:3D model converterOBJ to STL ConverterGLB to STL ConverterFBX to OBJ Converter

Open your STL for editing

Export the triangle OBJ locally, or choose paid tools for quad conversion and AI generated models.

Generate 3D Model