FitFileSize

Use FitFileSize from Claude

Add FitFileSize to Claude once, then ask in plain words for a file on your computer to fit an upload limit or a form's rules. Claude saves the result next to the original.

"Make ~/Downloads/signature.jpg fit the IBPS signature rules"

Saved ~/Downloads/signature.fit.jpg for IBPS signature (JPEG, 140 × 60 pixels, 10 KB to 20 KB): 10,240 bytes (10.0 KB), under the 20,000 bytes limit.

What you need

It does not work in Claude on the web or the phone apps, because those cannot reach files on your computer. Use the website there instead.

Set it up

Claude Desktop

Open Settings, then Developer, then Edit Config. Add this to the file, save it, and restart Claude Desktop. 

{
  "mcpServers": {
    "fitfilesize": {
      "command": "npx",
      "args": ["-y", "fitfilesize-mcp"]
    }
  }
}

If the file already has an "mcpServers" section, add the "fitfilesize" entry inside it.

Claude Code

Run this in a terminal:

claude mcp add fitfilesize -- npx -y fitfilesize-mcp

Cursor, VS Code and others

Cursor reads the same "mcpServers" block as Claude Desktop, in ~/.cursor/mcp.json. VS Code uses .vscode/mcp.json: 

{
  "servers": {
    "fitfilesize": { "command": "npx", "args": ["-y", "fitfilesize-mcp"] }
  }
}

Things to ask

Form presets set the size limit, the minimum size and the exact pixels in one go. They include the US visa photo, the Indian e-Visa, IBPS, SBI, RRB, SSC, NEET, JEE Main, CUET and GATE uploads, IRCC documents, Passport Seva documents abroad and Discord emoji and banners. Each one comes from the same rules as its page on this site, with the official source.

Every file keeps its format: a PNG stays a PNG. iPhone HEIC photos come back as JPEG.

What happens to your file

Claude sends the file to FitFileSize over HTTPS. It is compressed on our server, the same way as on the website, and deleted as soon as the result is saved on your computer. There is no account or API key. Uploads count toward the free limit of 30 files an hour. The privacy page has the details.

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