Health3 Biomarker Browser Extensions

Two free, open-source browser extensions that decode biomarker lab values right in your browser. Built and maintained by Health3.

Extension	What it does
Biomarker Unit Converter	Convert lab values between measurement units instantly (mg/dL ↔ mmol/L, ng/mL ↔ nmol/L, and 933 more)
Biomarker Explainer	Right-click any biomarker name on any webpage to see what it means, reference ranges from clinical sources, and related health topics

Both extensions cover 182 biomarkers, work completely offline, and collect zero user data.

---

Install

Browser	Unit Converter	Biomarker Explainer
Chrome	Install from Chrome Web Store	Coming soon
Edge	Coming soon	Coming soon
Firefox	Install from Firefox Add-ons	Coming soon
Opera	Coming soon	Coming soon

Listings are being rolled out across browser stores. In the meantime, you can load any extension as unpacked from this repository.

---

What's inside

1. Biomarker Unit Converter

A popup-based converter for biomarker lab values across all common medical measurement units.

Features:

• 182 biomarkers (Vitamin D, HbA1c, Iron, Cholesterol, Hormones, Vitamins, Cell counts, and many more)
• 935 supported unit conversions
• Mass ↔ molar (mg/dL ↔ mmol/L) using molecular mass
• Equivalent ↔ molar (mEq/L ↔ mmol/L) using valence
• Enzymatic activity (U/L ↔ µkat/L ↔ nkat/L)
• HbA1c (% ↔ mmol/mol ↔ fraction) with the IFCC formula
• Insulin (µIU/mL ↔ pmol/L) using the WHO standard
• Cell counts (×10⁹/L ↔ cells/µL ↔ G/L ↔ k/µL)
• Clearance rate (mL/min/1.73m² ↔ mL/s/1.73m²)
• Special cases for Urea/BUN, Hematocrit, and percentage concentrations
• Reference ranges from clinical sources (Tietz Textbook of Laboratory Medicine, StatPearls, Mosby's Diagnostic Reference, WHO, ADA, AHA, and peer-reviewed studies)

2. Biomarker Explainer

Right-click any biomarker name on any webpage to instantly see what it means, reference ranges, and related health topics. Works on patient portals, health articles, Reddit threads, research papers — anywhere biomarker names appear.

Features:

• One-click context menu lookup ("Explain with Health3")
• Plain-language descriptions for all 182 biomarkers
• All available reference ranges, transparently labeled by sex, age, source publication
• Related health topics
• Searchable popup library to browse all biomarkers
• No personalized matching — we show the data, you and your doctor make the interpretation

---

Privacy

• Zero data collection — both extensions run entirely offline
• No tracking, no analytics, no telemetry
• No accounts required
• All biomarker data is bundled as static JSON — no API calls, no remote scripts
• Permissions are minimal:
  • Unit Converter: none
  • Biomarker Explainer: contextMenus, activeTab, scripting (only to inject the explanation tooltip when you trigger the right-click menu)

See PRIVACY.md for the full extensions-specific privacy policy. (The Health3 mobile app has its own separate policy.)

---

Repository structure

biomarker-extensions/
├── shared/                    # Shared between both extensions
│   ├── data/
│   │   ├── biomarkers.json    # 182 biomarker definitions (name, description, molar mass, topics)
│   │   ├── units.json         # 935 unit definitions per biomarker
│   │   └── ranges.json        # 264 clinical reference ranges
│   ├── converter.js           # Unit conversion engine (faithful port of the Health3 mobile app's Dart logic)
│   ├── biomarker-lookup.js    # Name matching + lookup helpers
│   └── styles/
│       └── health3.css        # Brand styles (Manrope font, Health3 color palette)
├── unit-converter/            # Extension 1
│   ├── manifest.json
│   ├── popup.html / popup.js / popup.css
│   ├── _locales/en/messages.json
│   └── icons/                 # 16, 48, 128 px
├── lab-explainer/             # Extension 2 (a.k.a. Biomarker Explainer)
│   ├── manifest.json
│   ├── background.js          # Context menu registration
│   ├── content.js / content.css   # Inline tooltip injection
│   ├── popup.html / popup.js / popup.css   # Browse & search library
│   ├── _locales/en/messages.json
│   └── icons/
├── scripts/
│   └── build.sh               # Multi-browser packaging (Chrome / Edge / Opera / Firefox)
└── store-assets/              # Screenshots, promo tiles, store listings

---

Development & testing

Load unpacked

1. Open chrome://extensions/ (or edge://extensions/, about:addons for Firefox, opera://extensions/)
2. Enable Developer mode
3. Click Load unpacked
4. Select the unit-converter/ or lab-explainer/ folder

The extensions reference shared files via shared/ paths. For loading unpacked, create a symlink from each extension folder to the shared folder, or run ./scripts/build.sh and load the packaged version from dist/.

# Quick symlink setup for development
ln -sfn "$(pwd)/shared" unit-converter/shared
ln -sfn "$(pwd)/shared" lab-explainer/shared

Build packages for distribution

chmod +x scripts/build.sh
./scripts/build.sh

Outputs .zip files in dist/ for Chrome, Edge, Opera, and Firefox. Each is store-ready.

---

About Health3

Health3 is a mobile app that decodes blood work into actionable insights. Upload your lab results, get a personalized health score, track biomarkers over time, see how lifestyle changes correlate with your numbers, and receive evidence-based weekly insights.

These extensions are free standalone tools — they don't require a Health3 account. If you want personalized reference ranges, trend tracking, and lifestyle correlation across multiple lab tests, check out the Health3 mobile app.

• 🌐 Website: health3.app
• 📱 iOS: App Store
• 🤖 Android: Google Play
• ✉️ Support: support@health3.app

Health3 is built by Health3 AG, headquartered in Schlieren, Switzerland.

---

Contributing

Issues and pull requests are welcome.

Reporting issues

If a biomarker is missing, a unit conversion is wrong, or a reference range is outdated, open an issue with:

• Biomarker name
• The specific data that's wrong (current value, expected value)
• Source for the correction (clinical reference, publication)

Adding biomarkers or fixing data

The biomarker data lives in shared/data/. Contributions to this data should cite a clinical source (Tietz, Mosby's, peer-reviewed studies, etc.).

Code contributions

Pull requests for bug fixes, new features, or browser-compatibility improvements are welcome. The code is intentionally simple — vanilla JavaScript, no build step required for the extensions themselves.

---

License

MIT — see LICENSE.

Trademark notice and data source attribution are in NOTICE.

You're free to fork, modify, and redistribute these extensions. We just ask that you don't impersonate Health3 or use our trademarks (logo, "Health3" name) on derivative works.

---

Disclaimer

These extensions provide educational information about biomarkers based on published clinical references. They are not a substitute for professional medical advice. Always consult a qualified healthcare provider for medical decisions. Reference ranges shown are not personalized to your age, sex, or medical history.