ToolKnit

### 🔒 Privacy-First Architecture

- **Browser-only processing.** Files never leave the user's device. All conversion, compression, and editing happen client-side via Canvas API, MediaRecorder, Web Audio API, PDF.js, Tesseract.js, and Web Crypto API.

- **No accounts, no paywalls, no upsells.** No "premium tier." No feature gating. No sign-up required.

- **No invasive tracking.** Standard Google Analytics + Ahrefs pageview pixels only. No fingerprinting, no behavioral profiling.

- **Open source.** Public repo at [GitHub](https://github.com/2645149786-dotcom/awesome-free-browser-tools).

### 🛠️ 76 Tools Across 12 Categories

| Category | Count | Highlights |

|---|---|---|

| **PDF** | 7 | Compress, Merge, PDF↔Image, PDF↔Word, Extract Text |

| **Image** | 15 | Compress, Resize, Crop, Background Remover (AI), HEIC→JPG, Format Converters, Circle Crop, AI→PNG |

| **Video** | 4 | Compress (real-time Canvas+MediaRecorder), Video→GIF, Video Screenshot, Video→Audio |

| **Audio** | 6 | MP3↔WAV, Audio Converter, Noise Generator, Metronome, BPM Detector |

| **Text** | 8 | Character Counter, Case Converter, Lorem Ipsum, Text Diff, JSON Formatter, Markdown Preview |

| **Calculator** | 7 | Age Calculator, BMI Calculator, Percentage Calc, Tip Calc, Currency Converter, Loan Calc |

| **Time** | 5 | Stopwatch, Countdown Timer, World Clock, Pomodoro Timer, Date Calculator |

| **Chart** | 4 | Bar Chart, Pie Chart, Line Chart, QR Code Generator |

| **Creative** | 8 | Whiteboard, Drawing Board, Meme Maker, Signature Maker, Invoice Generator, Collage Maker |

| **Organization** | 4 | Item Locator, What to Eat, Spinner Wheel, Habit Tracker |

| **Self-Test** | 2 | Emotional Neglect Test, Attachment Style Test |

| **Emotional AI** | 1 | AI Ex-Partner Chat — distill an ex-partner's personality from chat records into an AI persona |

### 🎨 Design System

- **Dark B&W theme** with Space Grotesk font — minimal, fast, accessible

- **Responsive** — works on mobile, tablet, and desktop

- **PWA-ready** — Service Worker caching, installable as app

- **i18n** — English + Chinese (中文) with automatic locale detection

### 🌐 SEO & Performance

- Static HTML — no build step, no framework overhead

- Cloudflare CDN with Brotli compression

- Structured data (JSON-LD) on every page

- Sitemap with 177+ URLs

- IndexNow integration for instant search engine notification

### 🏗️ Technical Stack

| Layer | Technology |

|---|---|

| **Frontend** | Vanilla HTML + Tailwind CSS + Vanilla JS |

| **OCR** | Tesseract.js (WASM, client-side) |

| **AI** | DeepSeek API (user-provided key, client-side calls) |

| **Audio/Video** | Web Audio API, Canvas API, MediaRecorder |

| **PDF** | PDF.js, jsPDF |

| **PWA** | Service Worker + manifest.json |

| **i18n** | Custom JSON-based locale system |

| **Backend** | PHP 8.2 (stats API only) |

| **Hosting** | Nginx on BT Panel, Cloudflare CDN |

| **Analytics** | Custom tracker.js + Google Analytics + Ahrefs |

### For Everyday Users

- **Compress a PDF before emailing** — drag, drop, download. No account needed.

- **Convert iPhone HEIC photos to JPG** — batch process, no upload to unknown servers.

- **Make a GIF from a video** — set start/end, adjust FPS, export instantly.

- **Remove image background** — AI-powered, runs entirely in the browser.

- **Split an image into Instagram grid** — 3×3 auto-split, download as ZIP.

- **Check your emotional patterns** — 40-question psychological self-assessment, 100% private.

### For Professionals

- **Batch compress images for web** — reduce page load times without quality loss.

- **Extract text from 12+ document formats** — smart formatting preservation.

- **Generate invoices** — professional PDF invoices with line items and tax calculation.

- **Create charts from data** — bar, pie, line charts with export to PNG/SVG.

- **Format and validate JSON** — syntax highlighting, error detection, tree view.

### For Developers

- **Base64 encode/decode** — quick conversion without terminal.

- **QR code generation** — URL, text, WiFi, vCard QR codes.

- **Markdown preview** — live rendering with syntax highlighting.

- **Text diff** — compare two texts side-by-side with highlighted changes.

- **Keyboard tester** — verify every key on your keyboard works.

### For Emotional Wellness

- **AI Ex-Partner Chat** — upload chat screenshots (OCR-powered) or paste text records, distill your ex-partner's personality into an AI persona, have a conversation for closure. Sender identification uses position-based detection (left = ex, right = you) + user confirmation step. Uses your own DeepSeek API key — zero data upload to ToolKnit. Type `/let-go` to permanently delete everything when you're ready.

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## 📊 Quick Facts

- **76 tools**, all free, all browser-based

- **115 content pages** (73 blog guides, 9 tool tales, 33 changelog entries)

- **Zero server-side processing** for any tool — your files stay on your device

- **2 languages** — English & Chinese

- **Launched** March 18, 2026

- **Built by** Zihang Dong (solo developer)