Subtitle Conversion API

Convert between SRT, VTT and ASS subtitle formats with a single POST request. Free, keyless, no signup. Built on the same parser that powers DramaSub's translation pipeline.

Endpoint

POST https://www.dramasub.asia/api/tools/convert
Content-Type: application/json

Rate limit: 100 requests per day per IP (headers report your remaining quota). Max payload: 500 KB of subtitle text.

Request body

Field	Type	Notes
content	string	Required. The subtitle file text.
from	string	Optional. srt \| vtt \| ass. Auto-detected when omitted.
to	string	Required. srt \| vtt \| ass — must differ from `from`.

Example — SRT → VTT

curl -X POST https://www.dramasub.asia/api/tools/convert \
  -H "Content-Type: application/json" \
  -d '{
    "content": "1\n00:00:01,000 --> 00:00:03,500\nAnyong!\n",
    "to": "vtt"
  }'

Response

{
  "from": "srt",
  "to": "vtt",
  "cueCount": 1,
  "converted": "WEBVTT\n\n1\n00:00:01.000 --> 00:00:03.500\nAnyong!"
}

JavaScript example

const res = await fetch("https://www.dramasub.asia/api/tools/convert", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ content: srtText, to: "vtt" }),
});
const { converted, cueCount } = await res.json();

Errors

Status	Meaning
400	Invalid body, unsupported format, empty/unparseable content, from === to, or content over 500 KB
429	Daily IP limit reached — try again tomorrow or use the web tools

Need translation, not just conversion? The web converter and subtitle translator are free in the browser.

Building an AI agent? Drama search and subtitle conversion are available over the free catalog MCP server (at /mcp-catalog); token-authenticated subtitle translation runs over the translation MCP server (at /mcp).