Heartstring — Two Hearts, One Thread
Two phones, any distance: each of you rests a thumb on the camera and your real heartbeats braid into one glowing thread that buzzes with the other’s pulse.
Two phones, two fingertips, one luminous thread. Each phone reads its owner's pulse from the camera and streams it to the other — watch your two hearts try to beat as one. 💞
Invite your other half
Scan this on a second phone, or share the link / code.
You can start now — your partner can join any time.
Camera blocked 🔒
Allow camera access (tap the 🔒 / camera icon near the address bar), then press start again.
Your pulse is live 💗
As soon as your partner joins, both hearts light up the thread.
This device can't vibrate — you'll still see the beat light up.
Just for fun — not a medical device. Heartstring estimates each pulse from camera light and can be off, especially with movement or poor lighting. Don't use it for any health decision. Everything stays peer-to-peer between your two phones — no pulse data is ever uploaded.
Best on two phones with a back camera + flashlight, on the same Wi-Fi. The flashlight may switch on — that's normal and sharpens the reading.
Why you’ll love Heartstring — Two Hearts, One Thread
Instant & free
No signup, no paywall, no limits — Heartstring — Two Hearts, One Thread works the moment the page loads.
Completely private
Everything runs in your browser. Nothing you enter is ever uploaded or stored on a server.
Works on any device
Fully responsive and touch-friendly — use it on your phone, tablet or desktop.
Made for two
A little moment built to share with someone you love.
How to use it
Open it
No download and no login — the tool is ready right at the top of this page.
Use it
Enter your details or start interacting. Everything updates live as you go.
Get your result
Copy, download or share your result in a single tap. That’s it.
About Heartstring — Two Hearts, One Thread
Heartstring lets you share your real heartbeat with someone across any distance. Rest a thumb on each phone's camera, and the app detects your pulse to create a glowing thread that visualizes both hearts synchronizing. It's a free browser tool—no signup needed, no data leaves your device, just an intimate way to feel connected when you're apart.
Built for long-distance couples, Heartstring turns a simple biometric into something meaningful. When you sync your two phones, each heartbeat appears as a pulsing thread that mirrors the other person's rhythm. The buzzing sensation adds a tactile layer, making distance feel smaller for that moment you're connected together.
The technology works entirely in your browser by detecting blood flow through your fingertip via the camera sensor. Both heartbeats stay private on your phones—nothing is recorded, stored, or sent anywhere. It's a lightweight way to share something as personal as your pulse without sacrificing privacy.
Popular uses
Frequently asked questions
The app uses your phone's camera to measure blood flow through your fingertip. When you rest your thumb on the camera lens, it picks up the subtle color changes in your skin as blood pulses through. This technique is called photoplethysmography and works on most modern phones with decent camera sensors.
Yes. You each open Heartstring on your own phone and connect by sharing a room code or link. Your heartbeats sync in real time, so you see and feel each other's pulse even across continents. No accounts or personal data needed—just two phones and the app.
Completely. Everything runs in your browser on your device. Your heartbeat is never recorded, stored on a server, or sent anywhere. Once you close the app, there's no trace of the session. It's purely between your two phones.
Heartstring gives a real-time visualization of your pulse, but it's not a medical device. Lighting, camera quality, and how steady you hold your thumb all affect accuracy. It's reliable enough to feel the rhythm and sync with someone else, but don't rely on it for health monitoring.
Heartstring — Two Hearts, One Thread is 100% free — no signup, no watermarks and no usage limits. It’s one of 200+ free tools we build and give away.
Yes — it’s a playful, romantic little tool to enjoy together. Nothing leaves your device.
More Love Birds
From our collection of 317 free tools.
People also use
We built this. We can build yours.
Heartstring — Two Hearts, One Thread is one of 200+ free tools from Workaholic Developers — a software & AI studio. Need a website, app, AI agent or automation? Let’s talk.
🇮🇳 Built by Workaholic Developers
We built this little toy in days. Imagine what we’ll build for you.
AI agents, web apps, automation, custom tools — designed and engineered fast, on whatever tech fits the job. If you can describe it, we can build it.