Free, Open-Source Interview Prep App (No Subscription, No Account)
PrepOS is MIT licensed, free to download, no signup — bring your own OpenAI or Anthropic key for AI. Compare to paid prep SaaS.
Interview prep SaaS stacks subscriptions: question banks, mock interviews, AI credits with markup. PrepOS is free software — you download the Electron app, use LeetCode and GfG for free tiers, and only pay OpenAI or Anthropic if you enable AI chat.
What is free forever
- Desktop shell, dock, windows, focus mode, lockdown, sprint widget.
- Built-in web apps (LeetCode, HackerRank, feeds, etc.).
- Notes, playground, capture overlay — no cloud account.
What you pay for (optional)
Vision chat uses your API key. Keys are encrypted with Electron safeStorage — not stored on our servers because there are no PrepOS accounts. Students on a budget can prep without AI and add a key later.
Open source means trust
Audit ipc handlers, capture code, and storage on GitHub. Build from source with npm run dev if you do not trust the DMG. That transparency matters when an app sees your screen during Capture→AI.