How to Reduce Polygon Count in Blender

Every 3D model is made of small flat faces. More faces give more detail, but they also cost memory and speed. A statue for a render can have millions of faces. A character in a mobile game may need fewer than ten thousand.

AI-generated models and 3D scans come out dense by default. Our own sample fox has 60,000 triangles. That is fine for a desktop viewer, but it is three times the Roblox limit for a single mesh. So knowing how to trim a model is a basic skill.

First, check how many triangles you have

In Blender, open the Viewport Overlays menu at the top right of the 3D view. Turn on Statistics. Blender now shows the number of objects, vertices, edges, faces and triangles in the corner of the view.

Look at the Triangles number. That is the one engines care about. A four-sided face (a quad) counts as two triangles.

Pick a target before you start

There is no single right number. It depends on where the model will live. Here are real limits and ranks from platform documentation:

Platform	Triangle budget
Roblox, one mesh	20,000 maximum
Roblox, rigid accessory	4,000 maximum
VRChat avatar on PC	Excellent at 32,000 or fewer, Good up to 70,000
VRChat avatar on Quest	Excellent at 7,500 or fewer, Good up to 10,000

For your own game or website, pick a budget per model and test it on the slowest device you plan to support. A hero character seen up close can have more. A crowd of background animals should have much less.

For 3D printing, slicers handle big files well, so the limit is file size. A binary STL uses 50 bytes per triangle, plus an 84-byte header. So one million triangles is about 50 MB. Cutting that to 200,000 triangles gives a 10 MB file, and most prints will look the same.

How to reduce the polygon count with Decimate

The Decimate modifier removes faces while trying to keep the overall shape. Here are the steps.

1. Save a copy of your file. Decimation is hard to undo once applied.
2. Select the model in Object Mode.
3. Go to the Modifier tab (the blue wrench). Click Add Modifier, then Generate, then Decimate.
4. Keep the mode on Collapse.
5. Lower the Ratio. A ratio of 0.5 keeps about half the faces. A ratio of 0.1 keeps about a tenth.
6. Watch the Face Count shown in the modifier panel. Stop when it reaches your target.
7. Look at the model from the front, side and back. Check the face, hands, paws and any thin parts.
8. When you are happy, open the small arrow menu on the modifier and click Apply.

The modifier works live, so you can drag the ratio up and down and watch the model change before you commit.

The three Decimate modes

Blender’s Decimate modifier has three modes. Each suits a different kind of model.

Mode	How it works	Best for
Collapse	Merges nearby points, guided by a ratio	Organic shapes: characters, animals, scans, AI models
Un-Subdivide	Undoes rounds of subdivision	Models that were subdivided from a simple grid
Planar	Merges flat areas under an angle limit	Hard surfaces: buildings, furniture, boxes, robots

For most AI-generated characters, Collapse is the right choice. For a flat-sided prop, try Planar with a small angle, like 5 degrees, first.

Protect the details that matter

A plain ratio treats every part the same. But faces, eyes and fingers need more detail than a back or a belly. You can protect them.

1. Go to Weight Paint mode and paint the detailed areas red. Or select them in Edit Mode and assign them to a new vertex group.
2. In the Decimate modifier, pick that vertex group in the Vertex Group field.
3. Click the small invert button next to it, so the painted parts are decimated less.
4. Adjust the Factor to control how strong the protection is.

The Symmetry option is also useful. It keeps the left and right sides matching, which helps faces look even.

Decimating a rigged or animated model

Rigged models need extra care, because the skin weights must survive.

• Order matters. In the modifier list, drag Decimate above the Armature modifier before you apply it. Blender applies modifiers from the top down.
• Shape keys block it. Blender will not apply a modifier to a mesh with shape keys. Remove them, or keep a separate copy.
• Test poses afterward. Bend the knees and elbows and turn the head. If a joint now looks jagged or pinched, raise the ratio a little and try again.
• Keep joint areas denser. Use the vertex group trick from above on elbows, knees and shoulders.

Check the texture and shading

After you apply the modifier, look for three common problems.

• Stretched texture. Faces near UV seams can pull the image. Try a higher ratio, or protect those areas.
• Faceted look. Big flat faces can look blocky. Right-click the model and use Shade Auto Smooth to soften them.
• Holes or spikes. Very low ratios can fold thin parts. Raise the ratio, or fix the spot by hand.

When decimation is not enough

Decimation leaves a messy layout of long, thin triangles. That is fine for props, scans and background characters. It is not ideal for a main character that must bend a lot.

For those, use retopology. You rebuild the surface with clean, even four-sided faces that follow the shape. Blender has a Quadriflow remesh option, and you can also retopologize by hand with snapping. It takes longer, but the model will deform much better.

You can also make levels of detail (LODs). You keep the full model for close-up views and use lighter copies when the model is far away. Many game engines switch between them for you.

Export the lighter model

When the count is right, export in the format your destination expects:

• GLB for web, Godot and many viewers. See what a GLB file is.
• FBX for Unity and Unreal Engine. See how to convert GLB to FBX. Roblox Studio imports FBX, glTF and OBJ.
• STL or 3MF for printing. See 3MF vs STL, and check the result in our free STL checker.

Bake3D exports the full-detail mesh with its rig and animation. It does not make low-poly versions or LODs for you yet, so this guide is the step to take when a platform needs fewer triangles.