Media

Subtitle Reading Speed & Localization Auditor

Audit SRT, WebVTT, and ASS subtitles for CPS, duration, line length, overlaps, and translation expansion risk.

html· HTML resultOpen tool

Quick start

Call this tool from your code in three languages.

cURL

# 1) Request a presigned URL → returns { uploadUrl, storageKey }
curl -X POST 'https://api.elysiatools.com/api/upload/presign/subtitle-reading-speed-localization-auditor' \
  -H 'Content-Type: application/json' \
  -d '{"filename":"subtitleFile.ext","contentType":"application/octet-stream","size":12345}'

# 2) PUT the file bytes directly to the presigned uploadUrl
curl -X PUT '<presigned uploadUrl>' \
  --data-binary @/path/to/file.ext

# 3) Call the tool, passing the returned storageKey for each file field
curl -X POST 'https://api.elysiatools.com/en/api/tools/subtitle-reading-speed-localization-auditor' \
  -F 'subtitleText=1
00:00:00,000 --> 00:00:02,000
Welcome to the lesson

2
00:00:02,000 --> 00:00:03,000
This sentence is intentionally too fast.' \
  -F 'subtitleFile=uploads/2026/01/01/your-tool-1700000000000-abc123.ext' \
  -F 'inputFormat=srt' \
  -F 'preset=netflix-adult' \
  -F 'maxCps=20' \
  -F 'maxLineLength=42' \
  -F 'maxLines=2' \
  -F 'translationExpansionPercent=20'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/subtitle-reading-speed-localization-auditor

Parameters

Name	Type	Required	Description
subtitleText	textarea	No	—
subtitleFile	fileupload required	No	—
inputFormat	select	No	—
preset	select	No	—
maxCps	number	No	—
maxLineLength	number	No	—
maxLines	number	No	—
translationExpansionPercent	number	No	—

File-type parameters must be uploaded first via POST /upload/subtitle-reading-speed-localization-auditor, then the returned filePath is passed to the corresponding file field.

Response format

HTML result

JSON

{
  "result": "<div>Processed HTML content</div>",
  "error": "Error message (optional)",
  "message": "Notification message (optional)",
  "metadata": {
    "key": "value"
  }
}

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-subtitle-reading-speed-localization-auditor": {
      "name": "subtitle-reading-speed-localization-auditor",
      "description": "Audit SRT, WebVTT, and ASS subtitles for CPS, duration, line length, overlaps, and translation expansion risk.",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=subtitle-reading-speed-localization-auditor",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "subtitle-reading-speed-localization-auditor",
    "arguments": {
  "subtitleText": "1\n00:00:00,000 --> 00:00:02,000\nWelcome to the lesson\n\n2\n00:00:02,000 --> 00:00:03,000\nThis sentence is intentionally too fast.",
  "subtitleFile": "https://example.com/file.ext",
  "inputFormat": "srt",
  "preset": "netflix-adult",
  "maxCps": 20,
  "maxLineLength": 42,
  "maxLines": 2,
  "translationExpansionPercent": 20
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

File parameters accept a public file URL only (https://…). Local paths, data: URIs, and Base64 strings are not supported.

Questions or issues? Contact [email protected]