Short answer: the one inside the systems you already have. If your school runs Microsoft 365, start with Copilot; if you're a Google Workspace school, start with Gemini. Not because they're always the most capable — because they sit inside systems your school already governs, with data terms your IT lead already understands, no new logins, and nothing new to procure.
Why this beats picking the "best" tool
The tool matters far less than adoption. A capable tool your staff actually use, inside familiar software, beats a marginally better standalone tool that adds friction. Schools that embed one tool properly before adding a second consistently do better than schools that trial five at once and embed none. Our 2026 tools comparison covers the options honestly, including when standalone tools like ChatGPT or education-specific platforms earn a place.
The exception worth knowing
If your biggest workload pain is leadership documentation — SEFs, governor reports, Ofsted prep — purpose-built leadership tools can outperform general ones because they hold your school's context. See our review of AI tools for school leaders for when that's worth it.