A privacy-first, browser-native screen recorder.
Record your screen — nothing leaves your browser.
Kırmızı is a screen recorder that runs entirely in the browser. Users capture, edit, and download screen recordings without an account, an upload, or a watermark.
Every recording is assembled locally as a file and saved directly to the user's device. There is no backend for media — nothing is transmitted to a server, and nothing persists once the tab is closed. Privacy is a structural guarantee of the architecture, not a policy.
| Capability | Description |
|---|---|
| Local-only capture | The file is built on the device and never uploaded. |
| No account | No sign-up, no watermark, no tracking. |
| Audio | Microphone capture mixed with system audio via the Web Audio API. |
| Webcam track | The camera records as its own track — move, resize, and restyle the bubble after recording. |
| In-browser editor | Multi-cut timeline with filmstrip, per-segment mute and speed, animated zoom regions, and undo/redo. |
| Frame styling | Background presets, padding, rounded corners, and shadow, rendered into the export. |
| Export formats | MP4 when the browser can encode it, WebM everywhere else. |
| Capture settings | Resolution, frame rate, and countdown, chosen before recording. |
| Keyboard shortcuts | R record · S stop / split · Z zoom · Space play · Ctrl+Z undo. |
The application is a single Next.js project composed of two
surfaces — a marketing landing page (/) and the recorder (/record) — built on
a small set of web-platform APIs:
| API | Role |
|---|---|
navigator.mediaDevices.getDisplayMedia() |
Screen, window, or tab capture. |
getUserMedia() + Web Audio API |
Microphone capture and audio mixing. |
<canvas> + captureStream() |
Scene rendering (frames, zooms, webcam) and edited-clip re-encoding. |
MediaRecorder |
Encoding the stream to a Blob. |
URL.createObjectURL + <a download> |
Saving the file locally. |
No database, no authentication, and no server-side media handling are involved.
- Next.js (App Router) · TypeScript
- Tailwind CSS · shadcn/ui
- motion — animation
- next-themes — light / dark theming
- Type: Junicode (display), Bricolage Grotesque (UI), Geist Mono (technical)
bun install
bun dev # http://localhost:3000getDisplayMedia requires a secure context, so recording is available on
localhost during development and over HTTPS in production.
bun run build && bun run start # production buildKırmızı targets desktop Chromium (Chrome / Edge) and Firefox, where support is strongest. Safari's implementation is partial; the app feature-detects the required APIs and presents a clear fallback where they are unavailable. Microphone capture is reliable across browsers, while system-audio capture is best-effort and depends on the browser and operating system.
Released under the MIT License.