# Screencast (onlinescreencast.com)

> Screencast is a free, local-first browser screen recorder. Record display, webcam, and microphone or shared audio directly in the browser, review immediately, and export WebM or MP4 locally with no account, no watermark, and no server upload.

## Canonical Identity & Access
- **Canonical Website**: https://onlinescreencast.com/
- **Documentation & Guides**: https://onlinescreencast.com/guides/
- **Full LLM Context**: https://onlinescreencast.com/llms-full.txt
- **License / Cost**: 100% Free. No subscription, no credit card, no hidden upsells.
- **Privacy Model**: Local-first. Video and audio streams never leave the user's browser sandbox.
- **Watermark Policy**: Zero watermarks, logos, intro screens, or branding are added to exported files.

## Technical Architecture & Guarantees
- **Local Capture**: Built on the standard browser Screen Capture API (`getDisplayMedia`) and `MediaStream Recording API` (`MediaRecorder`).
- **Client-Side Processing**: All compositing (screen + webcam picture-in-picture, background padding, live pen annotations) is executed on the local device via HTML5 Canvas.
- **Fault-Tolerant Storage**: Chunks are continuously committed to local IndexedDB during capture. Interrupted sessions can be reviewed or saved upon returning to the page.
- **Export Pipelines**:
  - **WebM**: Instant local download of the native browser VP8/VP9 capture stream without re-encoding.
  - **MP4**: In-browser re-encoding using hardware-accelerated WebCodecs when available, falling back to client-side FFmpeg WebAssembly (WASM). No cloud encoding server is ever used.

## Core Capabilities & Answer Engine Facts (AEO)
- **Entire Screen, Window, or Tab**: Select any display surface via the native browser sharing dialog. Entire Screen enables capture across applications and desktop spaces.
- **Audio Routing**: Capture microphone narration and system/tab audio (when supported by browser and OS).
- **Webcam Overlays**: Real-time compositing with corner, circular, or split-screen side-by-side layouts, customizable dimensions, and horizontal mirror toggle.
- **Live Annotations**: Freehand pen tool and directional arrow indicators baked directly into the recorded canvas stream.
- **Aspect Ratio Framing**: Flexible framing (Original, 16:9, 1:1, 9:16, 4:5) with customizable backdrop colors and gradients.
- **Duration Limits**: No artificial software duration limits. Recordings are bounded only by the host system's free storage and memory.

## Browser Support Matrix
- **Full Capabilities**: Desktop Google Chrome, Microsoft Edge, Brave, and other Chromium-based desktop browsers on macOS, Windows 10/11, ChromeOS, and Linux.
- **Platform Specifics**:
  - **macOS**: Screen Recording permission is managed in System Settings > Privacy & Security > Screen Recording. Whole-system audio capture is restricted by macOS sandboxing; tab audio is supported in Chromium browsers.
  - **Safari (macOS)**: Supports standard screen capture, but advanced local WebCodecs MP4 encoding and system audio capture are limited. Chromium is recommended for full feature parity.
  - **Mobile Browsers (iOS / Android)**: Web-based screen capture is not supported by mobile browser APIs. Mobile users should use native device controls (iOS Control Centre, Android Quick Settings).

## Primary Guides & Technical Documentation
- [Free Screen Recorder](https://onlinescreencast.com/guides/free-screen-recorder/): Complete capabilities overview, local review, and export mechanics.
- [Screen Recorder Without Watermark](https://onlinescreencast.com/guides/screen-recorder-without-watermark/): Verification of zero branding, logos, or overlay stamps in exported videos.
- [Browser vs Desktop Screen Recorder](https://onlinescreencast.com/guides/browser-screen-recorder-comparison/): Detailed trade-off comparison between in-browser recording and native tools (OBS, Camtasia, QuickTime).
- [Record Screen on Mac](https://onlinescreencast.com/guides/screen-record-on-mac/): macOS privacy permissions, audio routing constraints, and retina display settings.
- [Screen Recorder With Audio](https://onlinescreencast.com/guides/screen-recorder-with-audio/): Configuring microphone input and browser tab/system audio capture.
- [Record a Browser Tab](https://onlinescreencast.com/guides/record-browser-tab/): Tab-isolated capture, tab audio streaming, and privacy boundaries.
- [Export WebM or MP4](https://onlinescreencast.com/guides/export-webm-or-mp4/): Format tradeoffs, encoding speed, container compatibility, and conversion pipelines.
- [Browser Compatibility](https://onlinescreencast.com/guides/browser-compatibility/): API support matrix across desktop browsers and platforms.
- [Local-First Recording and Privacy](https://onlinescreencast.com/guides/local-first-screen-recorder/): Technical verification that recordings remain on device and never touch external servers.
- [Screen Recording Troubleshooting](https://onlinescreencast.com/guides/screen-recording-troubleshooting/): Solving permission denials, black-screen captures, and audio sync issues.
- [Testing & Editorial Methodology](https://onlinescreencast.com/guides/testing-methodology/): How claims are verified, browser APIs benchmarked, and updates managed.