ASS ⇔ SRT 字幕変換ツール
Advanced SubStation Alpha（.ass）と SubRip（.srt）字幕ファイルをブラウザ内で相互変換。スタイルタグを除去しタイムコードを維持します。
ASS ↔ SRT Subtitle Converter
Convert between Advanced SubStation Alpha (.ass) and SubRip (.srt) subtitle formats. All parsing runs in your browser — files never leave the device.
Paste or upload to convert
よくある問題
YouTube rejected my .ass subtitle upload — how do I fix it?
YouTube only accepts SRT, VTT, SBV, and a few caption formats — ASS is not supported. Use this tool to convert your .ass file to .srt, then upload the resulting file. Karaoke and positioning tags are dropped because YouTube does not render them anyway.
Aegisub opened my SRT but every line is plain — how do I style it?
Aegisub can read SRT directly but treats every cue as plain text under the Default style. Convert SRT → ASS with this tool first, then open the .ass file. You will get a real V4+ style block to edit and styles applied to every Dialogue event.
My ASS subtitles have \\N line breaks but SRT output is one long line — why?
ASS uses \\N for hard line breaks inside one cue. This converter rewrites \\N as a real newline in the SRT output, which is the SRT-correct way to express the same break. If you still see one long line, the source file may be using \\n (soft break) or no break at all.
Why are my SRT timecodes slightly off after converting from ASS?
ASS stores time in centiseconds (1/100 s), while SRT uses milliseconds (1/1000 s). When converting, the centisecond value is multiplied by 10 to get milliseconds. No rounding errors should occur, but if you started with ASS files that already lost precision, the SRT inherits the same coarse boundary.
ワークフロー
ASS ⇔ SRT 字幕変換ツール とは？
Subtitle editors like Aegisub work in Advanced SubStation Alpha (ASS), but most streaming and embedding pipelines accept only SubRip (SRT). Going back and forth manually means hand-stripping every override tag and rewriting every timecode. This converter does both directions, runs entirely in the browser, and keeps your multi-line dialogue intact.
The tool is built for fansub workflows: parse the original ASS, drop the inline override blocks ({\\i1}, {\\b1}, {\\pos(…)}), normalize timecodes from centisecond precision (0:00:00.00) to SRT millisecond precision (00:00:00,000), and emit a clean cue list. Going the other way, every SRT line becomes a Dialogue event under a single style so editors can pick it up cleanly.
ASS ⇔ SRT 字幕変換ツール の使い方
1. Pick a direction: ASS → SRT or SRT → ASS.
2. Paste subtitle text into the left pane, or upload a .ass / .srt file.
3. Output appears instantly on the right.
4. Copy to clipboard or download with the correct extension.
使用例
ASS input:
Dialogue: 0,0:00:01.00,0:00:03.50,Default,,0,0,0,,Hello {\i1}world{\i0}
SRT output:
1
00:00:01,000 --> 00:00:03,500
Hello world活用例
1. Convert Aegisub-authored ASS to SRT before uploading to YouTube or a player that does not accept ASS.
2. Take downloaded SRT captions and convert to ASS so you can restyle in Aegisub.
3. Strip ASS karaoke and positioning tags down to plain SRT for translation memory tools.
4. Batch-prepare SRT from third-party subtitle services before merging into a fansub release.
よくある質問
Are my subtitle files uploaded anywhere?
No. Parsing happens entirely in your browser. Nothing is sent to a server, and there is no analytics on file content.
What happens to ASS override tags like {\\i1} or {\\pos(…)} when converting to SRT?
Override blocks are stripped because SRT does not support inline styling beyond a small subset of HTML. \\N and \\n are converted to real line breaks. If you need styling preserved, target a player that supports ASS directly.
Will SRT → ASS create a usable Aegisub project?
Yes. The output includes a minimal [Script Info], a single Default style, and every cue as a Dialogue event. Open it in Aegisub and add styles as needed.