---
title: ".ass file — what it is and how to open it"
description: "A .ass file is an Advanced SubStation Alpha Subtitle. A styled subtitle format with fonts, positioning and karaoke effects, common in anime releases. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/ass/
site: "At One Place"
---

# .ass files

**.ass file: Advanced SubStation Alpha Subtitle**

A styled subtitle format with fonts, positioning and karaoke effects, common in anime releases.

## What opens a .ass file

- **Windows:** VLC, MPC-HC, Aegisub, Notepad (built in)
- **macOS:** VLC, IINA, Aegisub, TextEdit (built in)
- **Linux:** VLC, mpv, Aegisub

## What a .ass file is

ASS extends the older SubStation Alpha format with full styling: typefaces, colours, outlines, on-screen positioning and timed karaoke effects. Fansubbed anime uses it heavily, which is where most people meet it. Players built on libass — VLC, mpv, MPC-HC — render it correctly; simpler players fall back to bare text or ignore the file, and any custom font it references has to be installed or embedded.

## Converting it

A .ass file is commonly converted to .srt, .vtt or .ssa. It is a plain text format, so any text editor can open and edit it directly.

## Details

- **Extension:** .ass
- **Full name:** Advanced SubStation Alpha Subtitle
- **Category:** Video
- **MIME type:** text/x-ssa
- **Created by:** SubStation Alpha / Aegisub project
- **Format:** Plain text

## Common questions

### How do I open a .ass file?

On Windows use VLC; on macOS use VLC; on Linux use VLC. A styled subtitle format with fonts, positioning and karaoke effects, common in anime releases.

### What is a .ass file?

Advanced SubStation Alpha Subtitle. ASS extends the older SubStation Alpha format with full styling: typefaces, colours, outlines, on-screen positioning and timed karaoke effects. Fansubbed anime uses it heavily, which is where most people meet it.

### Can I convert a .ass file?

Yes. It is usually converted to .srt, .vtt or .ssa, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.mp4 — MPEG-4 Part 14 Video](https://atoneplace.net/file/mp4/)
- [.mov — QuickTime Movie](https://atoneplace.net/file/mov/)
- [.mkv — Matroska Video](https://atoneplace.net/file/mkv/)
- [.avi — Audio Video Interleave](https://atoneplace.net/file/avi/)
- [.srt — SubRip Subtitle](https://atoneplace.net/file/srt/)
- [.webm — WebM Video](https://atoneplace.net/file/webm/)
- [.ts — MPEG Transport Stream](https://atoneplace.net/file/ts/)
- [.wmv — Windows Media Video](https://atoneplace.net/file/wmv/)
- [.mpg — MPEG-1 / MPEG-2 Video](https://atoneplace.net/file/mpg/)
- [.m4v — iTunes Video](https://atoneplace.net/file/m4v/)
- [.vtt — WebVTT Caption](https://atoneplace.net/file/vtt/)
- [.swf — Shockwave Flash Movie](https://atoneplace.net/file/swf/)

## Sources

- Media Types Registry — IANA (https://www.iana.org/assignments/media-types/)
- Official vendor product documentation — At One Place (/about/)