Node.js
Read local files, uploads, S3/R2 objects, and other byte sources.
JACOSUB to Markdown in your browser.
Convert JACOSUB files to GitHub-Flavored Markdown directly in your browser.
Your JACOSUB stays on your device. No upload. No account.
- npm @mdgate/subtitle
- license MIT
- runtime Node.js · Edge · browser
Starting local converter
Use JACOSUB to Markdown in your app
$
npm install @mdgate/subtitle
import { toMarkdown } from '@mdgate/subtitle';
const markdown = await toMarkdown(bytes);Pure TypeScript, Node.js, Cloudflare Workers, Edge, Browser, No Python, No native addons, No WASM, Zero third-party runtime dependencies
How JACOSUB to Markdown works
- JACOSUB
- cue parsing
- timing · text · emphasis
- GitHub-Flavored Markdown
Built for JavaScript runtimes
Cloudflare Workers
Parse subtitle files directly inside Workers without a media player.
Browser
Convert JACOSUB locally without uploading it to a server.
Edge
Run the same TypeScript converter in compatible Edge runtimes.
What @mdgate/subtitle extracts
- SRT and WebVTT timing
- ASS / SSA dialogue lines
- LRC lyrics
- MicroDVD .sub
- YouTube .sbv
- TTML
- Jacosub .jss
- Italic and other simple emphasis when the format carries it
Why @mdgate/subtitle
Runs where your JavaScript runs
No separate processing service. The converter is TypeScript you can call from Node.js, Cloudflare Workers, Edge runtimes, and browsers.
Local conversion
JACOSUB files can stay inside your application or browser.
Content detection
Recognizes JACOSUB files from their contents, not only the filename.
Deterministic parsing
The same JACOSUB file produces repeatable Markdown without model inference.
Small runtime surface
No Python. No native addons. No WASM. No third-party runtime dependencies.
JACOSUB for AI agents
Turn JACOSUB files into content your agent can actually work with.
- JACOSUB
- Markdown
-
- grep
- search
- chunk
- index
- cache
- cite
- reason
Need more than JACOSUB?
One format
@mdgate/subtitle
Your own set
@mdgate/core
+ @mdgate/subtitle
+ @mdgate/pdf
+ @mdgate/docx
Broad file support
@mdgate/converters
FAQ
Can I convert JACOSUB to Markdown without uploading it?
Yes. JACOSUB files can be converted locally in the browser.
Does JACOSUB to Markdown work in Cloudflare Workers?
Yes. @mdgate/subtitle runs directly in Cloudflare Workers.
Does it require Python?
No.
Does it require native addons or WASM?
No.
What does it output?
GitHub-Flavored Markdown.
Can I install only the JACOSUB converter?
Yes. Install @mdgate/subtitle instead of the complete converter set.