NeuralFill auto-fills web forms using your saved profile. No cloud. No tracking. Everything stays on your device, encrypted.
From installing the extension to filling your first form — takes about 2 minutes.
Add NeuralFill from the Chrome Web Store — click Add to Chrome and confirm the prompt. Pin the extension to your toolbar for quick access.
On first launch, NeuralFill generates a unique AES-256 encryption key for your profile data. A dialog will appear — copy and store this key somewhere safe (password manager, secure notes). Without it you cannot recover your data if you reinstall Chrome.
Click the NeuralFill icon → tap the + button to create a new profile. Give it a name (e.g. "Work", "Personal"), then fill in your details across the sections: basic info, address, professional & social, and any custom fields in Miscellaneous. Hit Save Changes when done.
Visit any website with a form. A floating badge will appear at the bottom-right of the page. Click Fill — watch your fields light up as they're filled instantly.
NeuralFill supports multiple profiles so you can switch between contexts — work applications, personal signups, freelance projects.
| Section | Fields |
|---|---|
| Basic | Full Name, Email, Phone, Date of Birth |
| Address | Street, City, State/Province, ZIP/Postal, Country |
| Professional | Job Title, Company, LinkedIn, GitHub, Twitter/X, Website |
| Miscellaneous | Any custom key-value fields you define |
Click Fill Now in the popup or press the keyboard shortcut to instantly fill all detected form fields on the current page. Fields are matched using two engines in sequence:
When NeuralFill detects a form on the page, a floating badge appears at the bottom-right corner showing how many fields were found. It has two buttons:
The badge disappears after 12 seconds of no interaction. Any click on the badge resets the timer.
Trigger fill from anywhere on the page without opening the popup:
⌘ + Shift + F on Mac · Ctrl + Shift + F on Windows/Linux
Click Preview in the popup to see a tooltip above each field showing what value will be inserted — without actually filling anything. Great for checking before committing.
Found a form with unusual fields that NeuralFill doesn't recognise? Use Scan & Learn in the popup. Gemini Nano scans the page, identifies unknown fields, and presents them for your review. Confirm the ones you want to save — they'll be stored in your active profile's Miscellaneous section and auto-filled on future visits.
For long-form questions like "Describe your experience" or "Why do you want to work here?" — upload your CV, portfolio, or bio to the Knowledge Base in the popup. NeuralFill uses Gemini Nano to generate tailored answers based on your documents. No data ever leaves your device.
Supported formats: PDF, DOCX, TXT. Upload in the Knowledge Base tab → then click ✦ Text on the badge or use the Generate button on any textarea.
Automatically use a specific profile on a particular site. Open the popup on that site → look for the site binding row at the bottom of the main view → select the profile → click Bind. Next time you visit, NeuralFill switches to that profile automatically.
Protect your profile data with a PIN. In the floating badge, click the lock icon to set a PIN. Once set, NeuralFill sessions last 15 minutes before auto-locking. You can also lock manually by clicking the unlock icon and entering your PIN. Useful when sharing your laptop.
Gemini Nano is Google's on-device AI model built into Chrome. NeuralFill uses it for smart field matching, text generation, and Scan & Learn. It runs entirely on your device — nothing is sent to Google's servers.
Chrome 138 or later is required. Check yours at chrome://settings/help. Update Chrome if needed.
Gemini Nano requires a capable GPU or Apple Silicon chip. Confirmed working on:
Older hardware or Intel integrated graphics may show "unavailable".
The Gemini Nano model requires approximately 22 GB of free disk space to download and run. This is the single most common reason the model fails to load — even if all flags are set correctly.
Free up disk space before enabling Gemini Nano. Check available space in System Settings → General → Storage (Mac) or Settings → System → Storage (Windows).
In a new Chrome tab, go to chrome://flags
Search for #prompt-api-for-gemini-nano and set it to Enabled.
Search for #optimization-guide-on-device-model and set it to Enabled BypassPerfRequirement. (Not just "Enabled" — it must be the BypassPerfRequirement option.)
Click the Relaunch button that appears at the bottom of the flags page. Do not just close and reopen Chrome — use the Relaunch button to preserve flag state.
After relaunch, Chrome will begin downloading the Gemini Nano model in the background. This can take several minutes depending on your internet speed. Check progress at chrome://components — look for Optimization Guide On Device Model. Once it shows a version number, the model is ready.
Open the NeuralFill popup → go to AI Setup. The requirements checker will show Chrome version, platform, and model status. All items should show a green checkmark. If not, see the troubleshooting section below.
Work through this checklist in order:
chrome://settings/help and update.#prompt-api-for-gemini-nano → Enabled AND #optimization-guide-on-device-model → Enabled BypassPerfRequirement.chrome://components and look for "Optimization Guide On Device Model". If absent, wait longer or try relaunching Chrome again.Fully quitting Chrome (⌘+Q on Mac, closing all windows on Windows) can reset experimental flag states. Always use the Relaunch button in chrome://flags instead of quitting and reopening. If you need to restart Chrome, re-enable the flags and relaunch again.
This can happen when Chrome's AI engine is under memory pressure on the first inference call. NeuralFill automatically retries once. If it still fails:
This component only appears after both Chrome flags are enabled and Chrome has been relaunched. Steps to force it:
chrome://components and click Check for update on any component to trigger a refreshNeuralFill uses field labels, IDs, and names to identify what each field is. Occasionally a field on a site uses an unusual name. To fix it:
NeuralFill will never fill password, CVV, card number, or expiry date fields regardless of how they're labelled.
Open the profile editor → scroll to the Miscellaneous section at the bottom → type the field name (e.g. "Employee ID") and its value → click + Add. You can add as many fields as you need. Hit Save Changes at the bottom when done.
Alternatively, use Scan & Learn on a site that has those fields — NeuralFill will detect them automatically.
Open the profile editor for any profile → click Export JSON. Save the file. On the new machine, open NeuralFill → click Import Profile from JSON and select the file.
Your encryption key is device-specific. You will need to re-enter your profile data if moving to a new installation, or keep the exported JSON as a backup alongside your key.
No. NeuralFill explicitly skips all password fields. It detects them by field type (type="password") and by name patterns (password, pass, pwd, secret). This exclusion cannot be overridden.
Similarly, payment fields — CVV, card numbers, and expiry dates — are also permanently excluded.
The lock icon reflects your PIN security state:
Once unlocked, your session stays unlocked for 15 minutes of activity. You can lock early by clicking the open padlock icon and confirming your PIN.
No. NeuralFill's Content Security Policy explicitly blocks all network connections (connect-src 'none'). Your profile data, documents, and AI interactions are 100% local. Gemini Nano runs on your device — not on Google's servers.
NeuralFill was built with privacy as a hard constraint, not an afterthought.
All profile data is encrypted with AES-GCM 256-bit before being written to storage.
The extension's CSP blocks all outbound connections. Nothing can be sent externally.
Gemini Nano runs locally in Chrome. Your documents and prompts never reach a server.
Password and payment security fields are permanently excluded from filling.
The encryption key is generated on your device. NeuralFill never sees it.
Optional PIN lock prevents access if someone else uses your browser or laptop.