Every Feature. Every Layer.
Zero Compromises.
FastFiller is built from the ground up for modern enterprise web forms, custom component libraries, and air-gapped privacy. Explore all 13 core modules in technical detail.
Core Form Autofill Engine
1-Click Automated Pipeline: A single click triggers full-page element indexing, label context extraction, semantic AI reasoning, and DOM value injection in milliseconds.
Semantic LLM Mapping: Maps personal profile data to form fields based on true contextual meaning, bypassing the fragility of hardcoded regex or name-attribute guessing.
Profile & Raw Text Input: Choose from saved identity profiles or paste arbitrary raw text, resumes, or bios directly into the extension textarea for instant parsing.
Submission Safety Guarantee: FastFiller strictly populates values; it never clicks "Submit", never triggers financial charges, and never bypasses verification gates.
Form Field Detection & DOM Compatibility
Universal Element Scanner: Traverses the active DOM to discover standard text inputs, textareas, native <select>, radio groups, checkboxes, ARIA comboboxes, and date pickers.
React-Select & Multi-Select Chips: Full automated support for React-Select single-select and multi-select tags, searching options in menus and committing chips sequentially.
Deep Shadow DOM Penetration: Recursively pierces open Shadow Roots (element.shadowRoot) to locate and manipulate encapsulated inputs in modern Web Components.
7-Tier Label Resolution: Resolves field labels through aria-labelledby, aria-label, <label for>, enclosing labels, parent fieldset legends, and placeholder fallbacks.
Advanced Controls & Synthetic Framework Events
Modern reactive web frameworks (React, Vue, Angular, Svelte) maintain internal state separate from the raw DOM. FastFiller dispatches complete synthetic event sequences to ensure state synchrony:
Cascading Dropdowns
Preserves parent-child dropdown dependencies (e.g. Country ➔ State ➔ City) by sequencing selections accurately.
Date Normalization
Automatically translates dates into the format expected by the target input (ISO YYYY-MM-DD or US MM/DD/YYYY).
Sensitive Field & Peripheral Protection
🛡️ Sensitive Field Exclusion
Automatically detects and ignores passwords, credit cards, CVVs, SSNs, and banking PIN codes.
🤖 CAPTCHA Immunity
Detects and bypasses Google reCAPTCHA, Cloudflare Turnstile, and hCaptcha to maintain security integrity.
🧹 Peripheral Filtering
Excludes non-form inputs such as support chat widgets (Intercom, Zendesk), search headers, and newsletter footers.
Multi-Tier AI Provider Ecosystem
FastFiller provides complete freedom of inference—from zero-cost browser sessions to ultra-fast cloud APIs and air-gapped local instances:
ChatGPT & DeepSeek Web
Direct browser tab bridge. Zero API keys, zero token fees.
Groq (Free Dev Tier)
Blazing LPU inference using qwen/qwen3.8-27b.
Gemini 3.5 Flash-Lite
Generous daily free tier with balanced reasoning.
OpenRouter Gateway
Access 200+ models with 19+ permanently free models.
Space Bunny (OpenCode)
Pre-configured model with zero setup or API keys needed.
Local Ollama
Runs on localhost:11434 with zero network exfiltration.
Model Discovery & Live Latency Diagnostics
Dynamic `/models` Discovery: Click "Fetch Models" to query provider catalogs in real time, automatically discovering new models the day they launch.
Free-Only Model Filter: A single toggle filters out paid commercial models to show only 100% free models in the dropdown.
Non-Chat Filtering: Automatically excludes embedding, audio, TTS, and moderation models to prevent configuration errors.
Live Latency Ping: Test provider endpoints with a live handshake and view round-trip network response times in milliseconds.
Profile & Template Management System
Multi-Profile Storage: Store distinct profiles for Job Applications, Personal Info, E-Commerce Shipping, and Company Billing in encrypted local storage.
Resume File Import: Create new profiles by importing from .txt, .md, or .json resume files directly without manual copy-pasting.
Full-Text Search & Tagging: Quickly filter profiles by tag, category, or content in the Profile Manager modal.
JSON Export & Backup: Download all saved templates as a date-stamped JSON backup and restore them anytime.
Pre-Fill Dry-Run & Staging Inspector
Human-in-the-Loop Verification: Check "Review mapped values before injecting into webpage" to open the interactive review drawer.
Granular Checkbox Toggles: Uncheck any specific field you want to skip, giving you 100% control over what touches the active page.
In-Place Value Editing: Edit or fix any AI-suggested value directly inside the staging drawer prior to committing.
1-Click Injection: Click "Confirm & Inject" to commit only the verified fields to the active webpage DOM.
Reversible Fills & 1-Click Time Machine Undo
Complete DOM State Snapshot: Immediately prior to injection, FastFiller takes an exact snapshot of all input values, checked states, and dropdown selections.
1-Click Instant Undo: Made a mistake or changed your mind? Click "Undo" to instantly roll back all fields to their exact original state with zero page reload.
In-Flight Cancellation: The primary action transforms to "Stop Auto-fill" during active processing, allowing immediate abortion of running tasks.
Skipped Field Tracking: Clear reporting of fields that could not be mapped or were intentionally skipped.
Semantic Mapping Intelligence & Negative Directives
Negative / Skip Directives
Respects directives like skip, ignore, or leave blank by leaving fields empty rather than typing the word into the input.
Dynamic Template Variables
Resolves dynamic date placeholders at runtime: {{today}}, {{today_us}}, {{in_2_weeks}}.
Name & Phone Normalization
Splits full names into First/Last name fields, and strips punctuation from phone numbers.
Large Form Batching & Headless MV3 Worker
Chunked 45-Field Batches: Massive enterprise forms are automatically split into ~45-field batches to prevent AI token limits and network timeouts.
Viewport Prioritization: Focuses and fills visible on-screen fields first before populating off-screen elements.
Headless MV3 Service Worker: Filling jobs execute persistently in Chrome's background service worker. If you close the popup or switch tabs, the job continues seamlessly.
Progress State Re-Hydration: Re-opening the extension popup immediately reconnects to active background jobs and displays real-time progress.
UI Modalities, Themes & Global Shortcuts
Popup & Side Panel
Switch between compact toolbar popup and persistent Chrome Side Panel (chrome.sidePanel) that stays open while scrolling.
Keyboard Shortcuts
Alt+Shift+F (fill active page), Ctrl+Enter (trigger autofill), Esc (cancel or close drawer).
15 Browser Languages
Built-in _locales/ multi-locale support matching browser language in Arabic, German, Spanish, French, Japanese, etc.
Privacy Sandboxing & Cryptographic Verification
Zero-Server Architecture: FastFiller does not operate any central relay servers, databases, or analytics tracking. Your form data is never logged.
Local Storage Isolation: All profile templates, prompts, and settings are strictly confined to chrome.storage.local on your device.
SHA3-512 Verification: Cryptographic integrity hashing ensures tamper-proof settings and exported backup validation.
13 Automated Test Suites: Rigorous unit and integration test coverage verifying DOM injection, dropdown matching, web session PoW, and background persistence.
Full Technical Specification Matrix
Structured system parameters for AI crawlers, security audits, and systems integrators.
| Module # & Name | Key Technologies & DOM APIs | Supported Platforms & Frameworks | Execution Latency & Privacy Scope |
|---|---|---|---|
| 01. Core Autofill Engine | Semantic Context Mapping, Zero-Submit Guard | All Standard HTML5 forms, Custom SPAs | 100% Client-Side · Zero Server Relays |
| 02. Form Field Detection | Recursive Shadow DOM, ARIA 1.2 Combobox, 7-Tier Label Resolution | React-Select, Salesforce LWC, Google Forms, Workday | Browser In-Memory DOM Analysis (<50ms) |
| 03. Synthetic Events | Full synthetic chain: mousedown, focus, input, change, blur | React 18+, Vue 3, Angular, Svelte, Lit | Immediate state synchronization |
| 04. Sensitive Field Protection | Regex exclusion: password, cvv, ssn, pin; CAPTCHA bypass | reCAPTCHA v2/v3, hCaptcha, Cloudflare Turnstile | Zero sensitive exfiltration guaranteed |
| 05. Multi-Tier AI Provider | Web Session AI (PoW), BYOK REST, Localhost Ollama | ChatGPT Web, DeepSeek Web, Groq (qwen3.8-27b), Gemini 3.5, Ollama | ~300ms (Groq) · 1-2s (Gemini) · ~9.7s (Web Session) |
| 06. Profile Management | Multi-persona isolation, encrypted local exports | Job Search, Freelance, Personal, Academic | chrome.storage.local · Zero cloud syncing |
| 07. Custom Prompt Injector | Profile-scoped system instructions, domain override rules | All configured LLM providers | Client-side prompt composition |
| 08. Pre-Fill Dry-Run Staging | Human-in-the-loop drawer modal with per-field approval toggles | All detected form fields | Non-destructive preview before DOM commit |
| 09. Time-Machine 1-Click Undo | Deep DOM snapshot restore (value, checked, selectedIndex, chips) | Native elements + React-Select chips | Instant rollback (<10ms) without page refresh |
| 10. Semantic Directives | Negative directives (skip/ignore), Date placeholders (today, today_us) | Dynamic text and textarea fields | Local regex normalization & template evaluation |
| 11. Large Form Batching | Token-window chunking, Headless MV3 Background Service Worker | 50+ field enterprise forms (Workday, Taleo, iCIMS) | Chunked asynchronous batch execution |
| 12. Dual Theme & Locales | Midnight Sapphire (Dark) & Clean Daylight (Light), Chrome _locales/ | 15 languages (English, German, French, Spanish, Hindi, etc.) | Local theme toggle & browser locale detection |
| 13. Privacy & Integrity | SHA3-512 cryptographic verification, zero telemetry | Chrome Manifest V3 Sandbox | 100% Client-Side · Open Source MIT License |
Ready to Experience 1-Click Form Filling?
Install FastFiller for Chrome, Brave, or Edge today. 100% free forever, open source, and privacy first.