chrome-devtools-mcp screencast supports WebM and uses filePath
Introduced 2026-04-22 · score 0.90
HOW TO USE IT
When saving an experimental screencast, start recording with `screencast_start` and a `.webm` `filePath`, then stop it with `screencast_stop`.
screencast_start({"pageId": <pageId>, "filePath": "<output>.webm"})screencast_stop({"pageId": <pageId>})WHY THIS HELPS
Save an experimental screencast as a WebM file.
BEFORE THIS CHANGE
The release note says the parameter was previously named `path`.
REQUIREMENTS AND LIMITATIONS
- Version: 0.23.0
- Availability: Experimental screencast command.
- pageId (required): ID of the target page.
- filePath: Output file path; `.webm` and `.mp4` are supported. A unique path is generated if omitted.
- --experimentalScreencast (required): Enables the experimental screencast tools; defaults to false.
- --experimentalFfmpegPath: Path to the ffmpeg executable.
- Prerequisite: Enable `--experimentalScreencast`; install ffmpeg and ensure it is available in the MCP server PATH.
- The screencast command supports `.webm` in addition to `.mp4`.
FIRST-PARTY EVIDENCE
- https://github.com/ChromeDevTools/chrome-devtools-mcp/releases/tag/chrome-devtools-mcp-v0.23.0
- https://github.com/ChromeDevTools/chrome-devtools-mcp/pull/1934
- https://github.com/ChromeDevTools/chrome-devtools-mcp/blob/chrome-devtools-mcp-v0.23.0/src/tools/screencast.ts
- https://github.com/ChromeDevTools/chrome-devtools-mcp/blob/main/docs/tool-reference.md
- https://github.com/ChromeDevTools/chrome-devtools-mcp/blob/main/docs/configuration.md
Check the installed version and the source before using it. Entry JSON