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Lint Manim before you render

Qual is the Manim-aware linter. It catches render-time errors, silent visual bugs, and per-frame performance traps without importing Manim or running your scene.

Get started Browse all 92 rules

uv tool install qual-manim
qual check .

Think Ruff for Manim scenes, with an understanding of Scene.play, mobject lifecycles, updaters, Cairo/OpenGL behavior, and render cost. Ruff and Pyright still check Python itself; Qual checks what Manim will do with it.

  • Catch crashes early

    Invalid Scene.play arguments, missing targets or saved state, invalid callback signatures, and other errors that otherwise surface during a render.

  • Find the wrong picture

    Lifecycle, renderer, ordering, updater, TeX, asset, and geometry mistakes that can finish successfully while producing the wrong result.

  • Explain render cost

    Per-frame construction, growing scene graphs, expensive callbacks, and resource-key growth with conservative multiplicity evidence.

  • Stay safe by default

    Qual never imports or executes Manim, plugins, or analyzed user code. An unresolved value becomes Unknown, not a high-confidence guess.

A general Python linter cannot see this

self.play(square.shift(RIGHT))
#                  ^ MLC102: shift() returns the mobject, not an Animation

label = always_redraw(
    lambda: MathTex(f"x={tracker.get_value():.2f}")
)
# MLP226: a frame-varying TeX key may create one disk asset per rendered frame

Qual resolves imports and aliases, follows project-local helpers, models Scene membership and animation cleanup, and distinguishes code that runs once from code that runs every frame. It reports a number only when the source and selected render profile prove it.

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Current support

Qual 0.3 targets Manim Community 0.20. It ships 92 implemented rules and native binaries for Linux, macOS, and Windows.