FIRST CH TOOLS LOCAL PROCESSING — IMAGES NEVER LEAVE YOUR DEVICE 日本語

FIRST CH TOOLS / 01 WEBP CONVERTER

Batch Image → WebP Converter

Converts PNG/JPEG images to WebP. Supports batch conversion and ZIP download. All processing happens on your device.

Drag & drop images here or click to choose files (PNG / JPEG, multiple allowed)
75–85 is a practical range (higher = better quality, larger files)

How to Use

  1. Set the qualityPick 1–100 with the slider. 75–85 works well for most images.
  2. Choose imagesDrag & drop or click to select PNG/JPEG files (multiple allowed). Conversion starts immediately.
  3. SaveDownload files one by one, or grab everything at once with "Download all as ZIP".

About This Tool

WebP is an image format developed by Google that is often 20–30%+ smaller than JPEG/PNG, which helps page speed and Core Web Vitals. This tool runs libwebp compiled to WebAssembly inside your browser, so your images are never uploaded to any server — safe even for logos and unreleased designs.

From AI Agents

This tool's WebP conversion logic (same libwebp encoder as the web tool) is also available as the webp_convert tool in our MCP (Model Context Protocol) server @first-ch/tools-mcp, callable directly by AI agents with no browser needed. See Using These Tools from AI Agents for setup details.

Install

claude mcp add firstch-tools -- npx -y @first-ch/tools-mcp

Example call

# example input passed to the agent
webp_convert(paths=["/path/to/image.png"], quality=80)

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