3D Model Converter

Upload a model you already have and write it out in the format your engine, slicer or viewer expects. Four directions run free in your browser; the rest run in the workspace.

Open the converter

FREE, IN YOUR BROWSER

Free 3D Model Converters That Run in Your Browser

These four directions run in your browser. The file is read in your tab and converted there, with no account, no upload and no cap on how many you run.

OBJ file formatSTL file format

OBJ to STL Converter

Take the OBJ a model site handed you and give your slicer the STL it asks for.GLB file formatSTL file format

GLB to STL Converter

Turn a Sketchfab or AI generated GLB into a printable STL, sized in millimetres.FBX file formatOBJ file format

FBX to OBJ Converter

Flatten an Autodesk FBX into the static mesh format that every other tool opens.STL file formatOBJ file format

STL to OBJ Converter

Bring a printable STL into Blender or Maya so you can carry on editing it.

HOW IT WORKS

How to Convert a 3D Model File

Three steps in the workspace, for the formats the browser tools do not write.

  1. Upload your model

    GLB, glTF, FBX, OBJ or STL. It goes to storage tied to your account.

    Up to 100 MB

  2. Pick the target format

    FBX, OBJ, STL, glTF, USDZ or 3MF, with an optional quad topology rebuild.

    Any input to any output

  3. Download the result

    The cost for the options you picked is on the button before you press it.

    2 credits, 3 with quad

FORMAT BOUNDARIES

What Survives a 3D Model Conversion

A conversion moves the mesh into a new container, and the destination format decides which other data comes along. Four things to plan around.

Geometry is the common core

Every route starts with a polygon mesh and produces another mesh format. Vertices and faces are the part every supported format shares, so the visible surface always comes through.

Materials need a capable destination

glTF carries PBR materials, OBJ relies on a companion MTL file, and STL has no field for colour or textures. Pick the target by what your next tool needs.

Quad topology changes only when requested

The workspace offers a quad rebuild as a separate option, off by default. Turn it on when a modeller still has editing to do.

Units require a deliberate check

glTF and GLB declare metres. OBJ, STL and FBX declare no unit, so check dimensions in the destination application after converting from them.

GAME ENGINES

Convert GLB to FBX for Unreal and Unity

FBX fits established engine pipelines

GLB is what AI generators and web viewers usually output, and Unreal, Unity, Maya and 3ds Max all import FBX. Upload the GLB, choose FBX and drop the result into that pipeline.

Quad topology supports later editing

Turn on quad topology when a modeller needs to keep shaping the mesh. It is a separate option, and the button shows the cost before the job runs.

A static mesh handoff can stay local

If you only need static geometry out of an FBX, the free FBX to OBJ converter runs in your browser with no account or upload. The workspace route covers the other output formats and the quad rebuild.

FORMAT COVERAGE

Every Format This 3D Model Converter Reads and Writes

Five input formats enter the workspace

Upload GLB, glTF, FBX, OBJ or STL. The limit is 100 MB per file.

FBX, OBJ and glTF cover engines and modelling

Choose FBX for engine and Autodesk workflows, OBJ for broad static mesh compatibility, or glTF for web viewers and WebGL applications.

STL, 3MF and USDZ serve specific destinations

STL is the plain geometry route for slicers. 3MF is the newer printing container that can carry colour and units. USDZ is what Apple AR Quick Look reads on iPhone and iPad.

My Assets removes a repeated upload

A model generated on Opolyo goes straight from My Assets into the converter. The finished file stays in My Assets so you can download it again.

WHY OPOLYO

Why Use the Opolyo 3D Model Converter

Pick the route that matches the file and the destination. Both show their limits before you start.

Four conversions run free and locally

OBJ to STL, GLB to STL, STL to OBJ and FBX to OBJ run in the browser with no account or upload. There is no limit on the number of files, and a 100 MB ceiling per file.

The workspace reaches six output formats

The signed-in workspace writes FBX, OBJ, STL, glTF, USDZ and 3MF from any of its five input formats. That covers engines, web, AR and printing from one asset library.

The selected cost appears before conversion

Workspace conversions use credits, and the button shows the figure for the settings you chose before the job starts. Quad topology adds to the cost and is off by default.

Completed files remain available

Workspace results stay in My Assets, so you can download them again later without rerunning the job.

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

3D Model Converter FAQ

Question not here? Ask by email.

  • Four directions run free in your browser: OBJ to STL, GLB to STL, STL to OBJ and FBX to OBJ. Each is linked above, and none of them asks for an account or an upload.

  • Writing FBX, glTF, USDZ and 3MF happens on our servers, since the browser tools cannot write those formats. Those conversions cost 2 credits, or 3 with quad topology turned on, and the figure for your options is on the button before you press it.

  • Not for the four browser converters. The workspace does need one, since files upload to storage tied to your account and finished conversions stay in My Assets.

  • GLB, glTF, FBX, OBJ and STL, up to 100 MB each. The same 100 MB ceiling applies to the browser converters, since everything runs in the tab.

  • No. 3MF is an output format here, and STEP is a CAD format this converter does not read. The input list is GLB, glTF, FBX, OBJ and STL.

  • Yes. Anything in My Assets can be sent straight to the converter, so there is no need to download it and upload it again.

  • The four browser tools hand the result straight to your download folder and do not use an account. Workspace conversions are stored in My Assets, so you can download a completed result again.

  • FBX, OBJ, STL, glTF, USDZ and 3MF. Any supported input can be written out as any of them.

  • No. STEP, STP and other CAD formats describe solids, and this tool converts mesh to mesh.

  • Apple AR Quick Look. A USDZ file is what lets an iPhone or iPad drop a model into the camera view straight from a web page.

  • The job reports the failure and the credits it charged go back to your balance automatically.

  • No. Quad topology is a separate option, off by default, and turning it on raises the cost shown on the button before the job begins.

  • STL for a plain print, since every slicer reads it. 3MF when the model has colour worth keeping, because STL has no standard place to store it.

  • FBX. Both engines import other formats too, but FBX is what their importers are built around.

  • glTF. It is the format web viewers and WebGL engines were designed for, and it keeps full PBR materials.

  • glTF and GLB declare metres. OBJ, STL and FBX declare no unit, so check dimensions in the destination application after converting from them. The free GLB to STL route is the one local pair that converts metres to millimetres.

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

Convert your 3D model

Start with a free browser conversion, or open the workspace for the other formats.

Generate 3D Model