Nanofill

About

Nanofill fills form fields with contextually appropriate dummy data using Chrome's built-in Gemini Nano (Prompt API / Summarizer API) — entirely on-device, with no external server or API key required.

Right-click any input, textarea, or select element to fill it instantly. Need to populate an entire form? One click fills every field with a coherent fictional identity — name, email, address, and free-text answers all consistent with each other.

KEY FEATURES

• Single-field fill — Right-click any field and select "Fill with Nanofill". The model reads surrounding labels, placeholders, and page content to generate a fitting value.

• Whole-form fill — Right-click and select "Fill entire form with Nanofill". The first fields are filled one by one (seeding a fictional identity), then the rest are filled in parallel. Already-filled fields are never overwritten.

• Smart length control — Single-line inputs get a short word or phrase; textareas scale output length to the element's visible height (short / medium / long).

• Page-aware context — The page text is summarized and used as context, so values make sense for the form's subject matter. Summaries are cached for 24 hours to keep subsequent fills instant.

• Consistent identity — Because later fields receive already-filled sibling values as context, the model naturally produces a coherent persona across name, email, address, and answers.

• Fully private — All processing runs locally via Chrome's on-device model. Nothing is sent to any external server.

REQUIREMENTS

• Chrome 138 or later
• "Optimization Guide On Device Model" must be available (check chrome://on-device-internals)
• On first use, the model download (~several GB) must complete before generation begins

SUPPORTED FIELD TYPES

• <input> — text, email, url, tel, password, number, date, search, and more
• <textarea> — paragraph-length output scaled to element height
• <select> — model picks one option based on the option labels

NOTE: Generated values are AI output and may not satisfy strict field validation. The extension cannot run on chrome:// pages or other restricted pages.