SRT to ASS Converter
Drop an SRT, get an ASS (Advanced SubStation Alpha) file ready to style in Aegisub or hard-sub with ffmpeg.
Drop your SRT file here
Converts to .ass — stays on your device
Why convert SRT to ASS?
- Starting a fansub project in Aegisub from an existing SRT — ASS is the format Aegisub, mpv, and every fansub tool use as their native working format.
- Adding custom fonts, colors, and positioning to plain SRT captions for a creator video, karaoke music video, or anime translation.
- Preparing subtitles for hard-subbing with ffmpeg (which natively supports ASS burn-in) instead of the more limited SRT overlay.
- Porting SRT subtitle tracks to mpv or VLC configurations that pre-style ASS with a custom script font.
- Building a template .ass file with one styled caption and copying the styling to future SRT imports for a YouTube channel's branded look.
- Translating a show on a team that uses Aegisub as the collaborative editor — everyone expects ASS-native files, not SRT.
How our converter works
Your SRT is parsed into a cue list, then wrapped in a standard ASS header with a single default style (Arial 20pt, white on black outline). Each cue becomes a Dialogue line with ASS's own timestamp format (H:MM:SS.cc centiseconds) and line breaks encoded as \N. Once open in Aegisub you can add styles, position lines, build karaoke effects, and do everything ASS is known for. Runs in your browser; nothing is uploaded.
SRT vs ASS — what's the difference?
| Feature | SRT | ASS |
|---|---|---|
| Structure | Numbered cues, plain text | Sections — Script Info, Styles, Events |
| Styling | Basic HTML tags | Full — fonts, colors, positions, karaoke, effects |
| Timestamp precision | Milliseconds | Centiseconds (one decimal less) |
| Universal playback | Yes — every player | Desktop only — VLC, mpv, MPC-HC |
| Best for | Uploads, desktop playback, editing | Fansubs, karaoke, hard-subbing, advanced styling |
Frequently asked questions
Can I load the result straight into Aegisub?
Yes. The output is standard ASS v4+ with a valid Script Info section, one Default style, and one Dialogue line per SRT cue. Aegisub opens it immediately.
What styling does the ASS default to?
Arial 20pt, white with a black outline, centered at the bottom of the frame — the Aegisub default. Everything from that point is yours to customize.
Does SRT italics (<i>) convert to ASS italics?
Not automatically — our converter emits plain text in the ASS Dialogue lines. For italics in ASS, add {\i1}...{\i0} override tags or set a style with italic=1 in Aegisub after import.
How precise are the timestamps?
ASS uses centisecond precision (10 ms) vs SRT's millisecond (1 ms). The converter rounds appropriately — rarely audible, rarely visible, but it's why ASS isn't recommended for frame-accurate dialogue in high-frame-rate content.
Can I use the ASS for hard-subbing with ffmpeg?
Yes. `ffmpeg -i video.mp4 -vf subtitles=output.ass out.mp4` burns the ASS in. Hard-subbing ASS (vs SRT) gives you the styling controls that make captions actually readable over varied backgrounds.
Are my subtitles uploaded?
No. The conversion runs entirely in your browser. Fansub scripts, unreleased karaoke cuts, and NDA-bound client content never leave your device.
About the SRT format
SRT (SubRip Text) is the lowest-common-denominator subtitle format — plain text, numbered cues, simple timestamps, supported everywhere. ASS (Advanced SubStation Alpha) is its power-user counterpart: a format designed by the fansub community around 2003 with fine-grained control over fonts, colors, positions, timing effects, karaoke, transforms, and per-line overrides. Aegisub, the dominant ASS editor, remains the tool of choice for anime fansubs, music video karaoke, and anyone who needs captions that do more than sit at the bottom in white. Converting SRT to ASS sets up that richer authoring environment — the source timings and text arrive intact, and everything stylistic becomes editable from there.