I Built a 4K Screen Recorder That Runs Entirely in the Browser

Description and use

A fully client‑side 4K screen recorder that runs in the browser without external software.

Problem

Need to record high‑resolution screen (4K) directly in the browser without external software.

Outcome

A fully client‑side 4K screen recorder that works in modern browsers, eliminating the need for external software.

Workflow

• 1. Request screen capture via navigator.mediaDevices.getDisplayMedia with video: {frameRate: 30, width: 3840, height: 2160}
• 2. Create a MediaRecorder instance with MIME type video/webm; codecs=vp9
• 3. On dataavailable events, push blobs into an array
• 4. When recording stops, concatenate blobs into a single Blob
• 5. Create a download link or upload the file to a server or cloud storage

Evidence

I Built a 4K Screen Recorder That Runs Entirely in the Browser — Here's How

Source