Best 2D Rigging Software with IK and FK in 2026

Moho is built around bones. Its features page describes forward and inverse kinematics, target bones, and Smart Bones, which drive corrective shapes so joints bend cleanly and can also act as control levers for faces and hands. Moho 14 adds Bone Dynamics on rotation, scale and translation for follow-through. For many solo animators it is the fastest way to a professional cut-out rig.

Spine is the most widely used 2D skeletal tool in games. Its IK constraints rotate one or two bones so the tip reaches a target, which is how most limbs are controlled. Note the tiers: Spine's user guide says IK constraints are not available in Spine Essential, so you need Professional for IK. Businesses with $500,000 or more in annual revenue must buy Enterprise.

Harmony is the industry tool for 2D production. Toon Boom positions Premium for sophisticated cut-out rigs, and its Premium documentation covers inverse kinematics alongside deformers. The Skeleton Controller lets one animation cycle drive characters that share a skeleton. It is the strongest choice for teams, and more than a solo animator usually needs.

Duik is the rigging and animation toolkit most After Effects animators use. It adds bones, IK controllers and automations such as walk cycles, blinks and springs. If you already pay for After Effects, it is the cheapest route to IK character rigs for explainer videos and ads.

Cartoon Animator turns layered artwork into rigged characters quickly and offers IK/FK motion editing, plus libraries of motions you can apply. It suits explainer video teams who want results quickly more than full manual control.

Rive has bones and an IK constraint, and pairs them with state machines, so a rigged character can look at the cursor, react to taps or follow app data at runtime. That is the key difference from video tools: the rig ships inside the product.

ExodeUI has a Bone tool, bone binding with weight painting and numeric weights, skinning on paths and meshes, and an IK constraint with per-bone angle limits, damping and stretch limits. Bone chains can run in FK or IK mode, and presets add walk, run and breathing cycles. Rigs sit next to state machines and spring physics, so a character can react to app state at runtime, and the MCP server lets AI coding tools build and adjust rigs too.

Grease Pencil objects can be bound to armatures, and Blender's IK constraint works on them, so you get proper FK and IK rigging for 2D drawings at no cost. The trade-off is Blender's complexity: it is a full 3D suite.

OpenToonz's Skeleton tool has three modes: Build Skeleton, Animate (FK) and Inverse Kinematics. It is a capable free option for cut-out characters, with the interface quirks of a studio tool.