Auto-rig a character

A skeleton and weights that hold up when the model moves

A character that is not rigged is a statue. Rigging it means two things: a skeleton of joints in the right places, and skin weights that say which joints move which part of the surface. This page does both, from the shape of the model alone, and hands back a GLB you can animate.

The joints are placed where a hand-made rig puts them: hips, three spine joints, neck and head, collarbones, shoulders, elbows, wrists, hips, knees, ankles and toes — plus end bones for the head and the toes, so the skull and the feet have a length. The names are the ones the animation world already agrees on, so a Mixamo clip plays on the result without renaming anything.

Weights are the part that usually goes wrong, and they are where the work went. The arms do not drag the chest when they swing. The thighs do not pull each other. The face turns as one piece with the head, and the teeth and eyes stay with it. That is the difference between a rig that survives an animation and one that has to be redone by hand.

The model is checked and corrected before it is rigged

A character exported at a hundred times its intended size, or with a bind pose that never worked, produces a rig that is wrong in ways nobody sees until it moves — and then it is hard to tell whether the rigger or the file was at fault. So the model is examined first, and the unambiguous problems are corrected: wrong scale, a broken bind pose, faces that are wound inside out.

Whatever it found is listed with the result, so you know what changed. Nothing ambiguous is touched.

Already has a skeleton? Keep it, or start again

Models from AI generators often arrive rigged, and the bones are usually fine — it is the weights that make the shoulders collapse and the belly stretch. When the file has a skeleton, the page says so and asks which you want.

Keep it, fix the weights. The bones, the bind pose and every animation in the file stay exactly as they are, and only the skin weights are solved again. This is the safe answer, and it is the one that fixes most broken characters.

Build a new one. The old bones are replaced with a fresh humanoid skeleton, and the animations that came with the file are carried onto it. Use this when the skeleton itself is the problem — joints in the wrong places, a missing spine, bones that do not correspond to a human at all.

A model with no skeleton skips the question: there is nothing to keep, so it is rigged from scratch.

Fingers, when the hands actually have them

Fingers are optional and off by default, because most generated characters do not have hands that can carry them. Switch it on when the fingers are modelled as five separate, clearly parted digits, and each hand gets three bones per finger with the standard names.

A hand that turns out to be a mitten, a fist, or a hand whose fingers touch is left ending at the wrist, and the result says which hand and why. That is deliberate: finger bones inside a mesh that has no fingers to separate produce weights that smear one digit into the next, which is worse than no finger bones at all.

What it expects, and what it will not do

It expects a standing humanoid, in an A- or T-pose, facing forward — the shape almost every text-to-3D and image-to-3D generator produces. Arms out or down both work. A model lying down, curled up, or posed mid-action will not be read correctly.

It does not rig animals, vehicles, or characters whose limbs are separate floating pieces. It is one humanoid skeleton, not a general-purpose rigger, and it says so rather than producing something that looks rigged and is not.

Clothing, hair and accessories that are part of the character are rigged along with it. A separate prop that is not attached follows the nearest joint.

Against the usual alternatives

Mixamo is the reference point, and it is a good tool: free, and its skeleton is the industry default. It also needs an Adobe account, it uploads your character to a server, it asks you to place markers on the chin, wrists, elbows, knees and groin by hand, and it takes FBX, OBJ or ZIP only. This page needs no account, uploads nothing, asks nothing before it starts, and reads GLB, GLTF, FBX, OBJ, DAE, STL, PLY, VOX and VRM.

The rig your generator gave you is worth keeping when the bones are sane — which is why this page offers to fix its weights rather than replace it. Their weights are the weak part; their joint placement usually is not.

Blender will do all of this and more, with automatic weights from an armature you position yourself. It is the right tool when you want control over every joint. It is a large download and a long afternoon when you want a character to walk today.

After the rig

Drop the result into the editor to play an animation on it immediately: the built-in library covers idle, walk, jog, sprint, jump, crouch, punch, dance and more, and any FBX or GLB animation you own can be imported onto it.

The editor also lets you drag any joint on a front view of your own character and re-solve the weights against it — the two-minute fix for a shoulder that sits a centimetre too low. And it exports the finished character with the bone names, root bone and bind pose that Godot, Unity or Unreal expect.

How to use it

1. Drop your character in the box above. Nothing is uploaded — it is read in this tab.
2. If the file already has a skeleton, choose whether to keep it or build a new one. If it does not, there is nothing to choose.
3. Switch on fingers only if the hands have five clearly separated digits.
4. Press "Rig it", then download the animation-ready GLB.

Questions

Is my model uploaded?

No. The whole thing runs in your browser tab, on your machine. Nothing is sent to a server, there is no account, and there is no file size limit.

Which bones do I get?

A standard humanoid skeleton: hips, three spine joints, neck, head, collarbones, upper arms, forearms, hands, thighs, shins, feet and toes, with end bones for the head top and the toe tips. With fingers switched on, three bones per finger on each hand. The names follow the Mixamo convention, which Unity, Godot and Unreal all recognise.

Will Mixamo animations play on the result?

Yes. The bone names match, so a Mixamo clip applies directly. The editor also retargets clips whose skeletons do not match by name.

My character already has a skeleton but it deforms badly. What should I pick?

Keep the skeleton and let the weights be solved again. Bad deformation on a generated character is almost always the weights, not the joints — and keeping the skeleton means every animation in the file keeps working.

What happens to my animations if I rebuild the skeleton?

They are carried onto the new bones. A clip whose bones have no counterpart on a humanoid skeleton is left behind, and the result says how many.

Does it need a T-pose?

No. A- or T-pose both work, as long as the character is standing and facing forward. Arms down at forty-five degrees is the shape most generators produce, and it is fine.

Can it rig an animal or a four-legged creature?

No. This is a humanoid rigger — two arms, two legs, one head. A quadruped, a vehicle or a character built from separate floating pieces will not come out right.

A joint is in slightly the wrong place. Can I move it?

Yes, in the editor: your character is drawn from the front with every joint on it, you drag the ones that are off, and the weights are solved again against the joints you placed. It is the same idea as marking up a photo, and it takes about a minute.

How do I animate a 3D model that has no bones?

It needs a skeleton and skin weights first — that is what this page produces. Once it has them, any humanoid animation clip can drive it: the built-in library in the editor, a Mixamo download, or an FBX from anywhere else.

The other tools

• Batch processing — Run any Rig Bake tool over a whole folder of models and get one zip back.
• Reduce polygons — Cut the triangle count of a GLB, GLTF, FBX, OBJ, DAE, STL, PLY, VOX or VRM — or a zipped model folder — and keep the textures. Runs in your browser, no file size limit, nothing uploaded.
• Quad remesh — Rebuild any mesh as clean quads with real edge flow, in your browser — with the UVs and textures rebuilt onto the new surface too. Reads GLB, GLTF, FBX, OBJ, DAE, STL, PLY, VOX and VRM, with no file size limit.
• Bake a normal map — Bake high-poly detail into a normal map (and ambient occlusion) for a light version of the model — the xNormal workflow, in your browser. Drop one heavy model, or add your own low-poly and the maps bake onto its UVs. No upload, no account, no file size limit.
• Compress GLB — Name the file size you need and get it. Drop a GLB, GLTF, FBX, OBJ, DAE, STL, PLY, VOX or VRM — or a zipped model folder — and the page works down a list: dead weight first, then the mesh bytes, then the textures, and only then the triangles. In your browser, no file size limit.
• FBX to GLB — Convert an FBX — Mixamo, Blender, an AI generator — into a GLB, with the centimetre scale fixed on the way through. Any size, in your browser, nothing uploaded.
• Check a 3D model for problems — The Model doctor: find what is wrong with a model before it wastes your afternoon — wrong scale, broken bind pose, inverted normals, overlapping UVs, holes. Reads GLB, GLTF, FBX, OBJ, DAE, STL, PLY, VOX and VRM, any size, in your browser.
• Repair a 3D model — Weld split vertices, drop degenerate faces and stray islands, fill holes, flip inverted normals. GLB, GLTF, FBX, OBJ, DAE, STL, PLY, VOX or VRM — any size, in your browser, nothing uploaded.
• Pixel art from 3D — Drop an animated model, get a pixel-art spritesheet. The palette, the dither and the direction set are already chosen — fine-tuning lives in the editor.
• GLB to STL — Convert a 3D model to a printable STL — scaled to real millimetres, turned Z-up, and told plainly whether it is watertight. GLB, GLTF, FBX, OBJ, DAE, PLY, VOX or VRM in, any size, in your browser.
• OBJ to GLB — Convert an .obj into a GLB that engines and browsers read. Geometry and UVs travel; OBJ has nothing else to carry. Any size, in your browser, nothing uploaded.
• GLB to USDZ — Convert a 3D model to USDZ for AR Quick Look on iPhone and iPad — textures included. Any size, in your browser, nothing uploaded.
• LOD Generator — Turn one model into a chain of LOD meshes — each level a measured step down, zipped together with per-level stats. In your browser, nothing uploaded.
• Merge Materials — Merge every mesh and material into one mesh with one atlased material — draw calls collapse to a single one. In your browser, nothing uploaded.
• Everything else Rig Bake does — rigging, retargeting, spritesheets, VFX.