Forgetless — AI-Powered Spaced Repetition

"In the age of instant answers, the real edge is remembering. If AI is the flood, Forgetless is the dam."

Overview

Forgetless is a production flashcard app that pairs four frontier LLMs (OpenAI, Anthropic, Gemini, Mistral) with FSRS v6 — the same scientifically-validated spaced repetition algorithm used by Anki. The thesis: as generative AI commoditizes on-demand answers, durable long-term memory becomes a compounding human advantage. Forgetless turns any input — PDFs, YouTube videos, images, plain text — into memory you actually keep.

Live at forgetless.app. Launched publicly in early 2026 with founder pricing and a full freemium tier.

🎯 Core Value Props

1. AI card generation in 5 seconds

Type any concept; pick any of four AI providers; get a clean flashcard. Batch mode generates an entire deck from a single prompt.

2. FSRS v6 — not a toy algorithm

Runs the same Free Spaced Repetition Scheduler that powers modern Anki. Per-user parameter optimization. Landing stats: 91% average retention and 30% fewer reviews for the same recall.

3. Multi-modal input

• PDF upload → auto-generated cards from academic papers or textbooks
• YouTube transcripts → paste a URL, get flashcards from the video (Pro)
• Image upload → OCR + AI summarization
• Text input → traditional manual creation

4. Cloze deletion + card types

Inline fill-in-the-blank with word-level hiding. Fact-checking pass via Mistral on generated cards.

5. Social layer

Public deck sharing with fork-to-library, daily/weekly/staff-pick discovery, embeddable iframe widgets ("Powered by Forgetless" CTA) for blogs, Notion, and Obsidian. Anki .apkg export with watermark card.

💰 Freemium Business Model

Free ($0 forever) — Unlimited cards, 10 AI generations/month, full FSRS engine, import/export.

Pro — Founder pricing at $9/mo (locked forever for first 100 slots). 50 AI generations/day, YouTube cards, batch generation, advanced analytics (retention curves, weak-card detection), no branding on shared decks.

Student — 50% off with academic email verification.

🛠️ Tech Stack

Frontend

• Next.js 16 App Router with React Server Components
• React 19, TypeScript, Tailwind CSS
• PWA with standalone mode, custom theme color, offline-ready service worker
• Rendered via sql.js (WASM) for in-browser SQLite (Anki .apkg parsing)

Backend

• Supabase (Auth, Postgres with RLS, Storage, Edge Functions)
• 4 AI providers behind a unified abstraction: OpenAI, Anthropic, Gemini, Mistral
• FSRS v6 implementation in TypeScript with per-user parameter optimization
• Stripe (subscriptions with founder-pricing lock, student discounts, referral credits)

Ops & Growth

• PostHog for product analytics (anonymized)
• Programmatic SEO — 30+ landing pages including /compare/{anki,quizlet,remnote}, /youtube-to-flashcards, /pdf-to-flashcards, /learn/{topic}, /flashcards/{slug}
• Schema.org Course JSON-LD for every public deck, dynamic OG images
• Referral system — +25 card slots per signup, free Pro month per 3 referrals
• Creator rewards — revenue share loop for deck creators

🏗️ Engineering Highlights

FSRS v6 in the browser

Anki's scheduler reimplemented in TypeScript, running entirely client-side so review latency is zero. Per-user weights are optimized from review history without sending card contents off-device.

Multi-provider AI abstraction

A single generateCard() call routes to the user's chosen provider with consistent schema, retry logic, and token budgeting. Falls back across providers if one is rate-limited.

Anki interop

Full bidirectional compatibility: import .apkg decks (parsed via SQLite WASM), export watermarked .apkg files that work in Anki Desktop, AnkiDroid, and AnkiMobile.

Shared-deck preview with soft paywall

Unauthenticated visitors can flip 10 cards + see 3 blurred cards of a shared deck before signing up. Converts curiosity into accounts without the usual hard gate.

📈 What Makes This Hard

Forgetless is not another "ChatGPT wrapper for flashcards." The hard parts:

• Getting FSRS v6 exactly right so recall matches Anki's
• Keeping AI generation costs sustainable with heavy free-tier usage (4 providers, daily limits, caching)
• Building bidirectional .apkg compatibility without breaking Anki semantics
• Shipping a PWA that feels native (iOS install, offline review, notifications)
• Solving onboarding for a non-obvious concept (spaced repetition is weird until you try it)

🎓 Why It Matters

Every knowledge worker is drowning in bookmarks they'll never re-read and summaries they'll forget. Forgetless bets that the bottleneck in the AI era isn't access to information — it's internalization. The product is small on purpose: a dam, not an ocean.