Luminance built its reputation as the heavy artillery of legal AI, excelling at the kind of massive contract review that happens during acquisitions or regulatory investigations. It's powerful, sophisticated, and trusted by global law firms that need to analyze thousands of documents with precision. Spellbook took a different path: it embedded itself directly into Microsoft Word as a contract drafting co-pilot, offering real-time suggestions and language improvements without forcing lawyers to learn a new platform. The meaningful difference isn't AI quality—both are impressive—it's about workflow integration versus analytical depth. Luminance requires you to upload documents to its platform, making it ideal for project-based work but less convenient for daily drafting. Spellbook disappears into your existing process, popping up helpful suggestions as you write. Luminance also carries enterprise-grade pricing that signals its target market clearly. Choose Luminance if you're at a law firm handling complex due diligence or managing large contract repositories where deep analysis justifies the investment. Pick Spellbook if you're an in-house counsel, business owner, or small firm attorney who needs practical daily assistance without disrupting how you already work. For most business professionals reading this, Spellbook's combination of accessibility and integration wins.