Zero-Key AI
Free Web Session AI Setup Guide
Published: September 30, 2026 · Documentation
What is Web Session AI?
Most AI extensions require you to pay monthly subscriptions or purchase costly developer API tokens. FastFiller eliminates this barrier with Web Session AI.
FastFiller directly bridges into your existing, logged-in browser session on official AI web interfaces. As long as you have a free account and keep a tab open, you get unlimited, 100% free form filling forever.
Supported Web Engines
1. ChatGPT Web (chatgpt.com) $0.00 Forever
FastFiller connects directly to your active browser login at chatgpt.com. It handles OpenAI's Sentinel proof-of-work challenges automatically in milliseconds.
✓ Open chatgpt.com in any browser tab and sign in.
✓ In FastFiller, set the engine to Web Session AI → ChatGPT Web.
✓ Start filling any form with zero API keys required.
2. DeepSeek Web (chat.deepseek.com) $0.00 Forever
FastFiller connects directly to your active login at chat.deepseek.com, utilizing our client-side Keccak-f[1600] PoW solver to process form reasoning at zero cost.
✓ Open chat.deepseek.com in a tab and sign in.
✓ In FastFiller, select Web Session AI → DeepSeek Web.
✓ Enjoy high-reasoning form filling on complex applications and ATS portals.
Troubleshooting Web Sessions
- "Session Expired" or "Not Logged In": Simply navigate to chatgpt.com or chat.deepseek.com, log in with your credentials, and refresh your target form.
- Cloudflare Verification: If a Cloudflare challenge appears on the web tab, solve it once in the open browser tab; FastFiller will resume normal operation immediately.