Fillin — AI Form Filler

Context-aware autofill that writes, verifies, and never submits forms for you.

Fillin helps you complete online forms faster while keeping you in control. Instead of blindly inserting generic text, Fillin reads the current page, understands what each field is asking for, plans suitable content, fills the fields one by one, and verifies that the page accepted the result. It never submits a form on your behalf—you always review and submit the final content yourself. WHAT FILLIN CAN DO • Fill text inputs, text areas, dropdowns, radio buttons, checkboxes, and rich-text editors • Understand labels, placeholders, field constraints, nearby text, and page context • Read an article before generating a relevant comment • Distinguish article titles from body editors and generate complete long-form drafts • Match generated content to the website language, including English, Chinese, and German • Handle many React forms, embedded frames, and modern web editors • Preserve existing values unless you explicitly request a rewrite • Verify every result after writing it • Undo the current filling operation • Fill eligible empty fields with clearly synthetic local data when AI is unavailable USE YOUR OWN AI SERVICE Fillin supports OpenAI, OpenRouter, DeepSeek, and other services that provide an OpenAI-compatible /chat/completions API. You can configure your own endpoint, model, and API key, save optional reusable profile information, and provide a specific instruction for each task. PRIVACY AND CONTROL Fillin has no developer-operated backend. Your API settings and optional profile are stored locally on your device using chrome.storage.local. When you start a task, only the relevant page context, field information, your instruction, and the profile you choose to use are sent directly to your configured AI provider. Fillin does not collect browsing history, cookies, or analytics data. It does not read existing passwords and never automatically submits forms. Your settings remain available after browser restarts, extension reloads, and extension updates. You can also export a local configuration backup. Uninstalling the extension removes data stored by Chrome. Please review all generated content before submitting a form.