Free is not a crippled trial -- it's a real cascade of fast, efficient models with cited web sources, meant to answer most everyday questions well on its own. You should be able to use Free indefinitely without hitting a wall on basic use.
What upgrading actually changes:
- Named frontier models -- Pro and above let you pick Opus, GPT-4o, Grok or Gemini directly instead of the free cascade choosing for you.
- Deeper research -- more sources pulled per answer, and a multi-step deep-research mode instead of a single-pass search.
- Higher daily limits -- useful once Lumen is part of your daily workflow rather than an occasional lookup.
- Lumen-Pro automation and API access sit alongside the answer engine for teams that want scheduled agents or to call the router programmatically.
Exact current prices and what's included at each step live on the Pricing page -- we'd rather you check there than have a blog post quietly go stale.