PPTArena: A Benchmark for PowerPoint Editing

We introduce PPTArena, a benchmark for PowerPoint edit-ing that evaluates how agents modify real slides from natural-languageinstructions. Unlike benchmarks that rely on image-PDF renderings ortext-to-slide generation, PPTArena features 100 decks with over 1,300human-curated edits across 2,125 slides, spanning text, charts, anima-tions, and professional master styles. Each edit pairs a ground-truthdeck with a target rubric and is scored by two Vision-Language Model(VLM) judges: one rates instruction following from structural diffs, theother visual quality from slide images. On top of this benchmark, wepresent PPTPilot, a structure-aware agent that plans semantic edit se-quences, routes between programmatic tools and deterministic XMLoperations, and verifies each result in an iterative plan-edit-check loop.PPTPilot outperforms strong VLM-based agents by more than 10 per-centage points on compound, layout-sensitive, and cross-slide edits, withlarge gains in visual fidelity and deck-wide consistency. Despite this, allagents still struggle on long-horizon, document-scale tasks, underscoringhow hard reliable PowerPoint editing remains. We publicly release ourcode: https://github.com/michaelofengend/PPTArena.