Leo: making centuries-old handwriting readable

Archives are full of documents almost nobody alive can read: faded ink, archaic scripts, damaged pages. Leo pairs AI transcription with a reading experience built for the people who work with these sources: drop a scan in, and get faithful, readable English out, side by side with the original.

We built the platform end to end: a Next.js frontend over a NestJS and Supabase backend, Clerk for authentication, and Stripe powering the subscription flows. The craft is in the reading room itself: OpenSeadragon drives buttery deep-zoom over ultra-high-resolution scans so researchers can inspect individual pen strokes, and DnD Kit makes bulk uploads feel effortless. Leo is live and taking subscribers at tryleo.ai.

Leo went from an idea to a live product with paying subscribers. Researchers upload a scan and get faithful, readable English side by side with the original, then zoom into individual pen strokes to check the transcription.

Stripe subscriptions and Clerk-secured accounts mean the business runs itself: sign-up, payment and access all work without manual steps.