Subtitle Converter (SRT, VTT, SUB) — Convert subtitles between the three most common text-based formats: SRT (SubRip), WebVTT (the HTML5 video standard), and MicroDVD SUB (frame-number based). Paste a file, pick the source and target, and copy the result.
Subtitles are parsed and converted in your browser. Nothing is uploaded to a server.
Was Subtitle Converter (SRT, VTT, SUB) useful?
Subtitle Converter (SRT, VTT, SUB)とは？
Convert subtitles between the three most common text-based formats: SRT (SubRip), WebVTT (the HTML5 video standard), and MicroDVD SUB (frame-number based). Paste a file, pick the source and target, and copy the result.
Two extra moves: shift every cue by a number of milliseconds (useful when audio and subtitles drift) and scale every cue by a factor (useful when the playback speed is wrong). The whole tool runs locally — the subtitles never leave the page.
使い方
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Pick the source format
SRT, VTT, or SUB. Auto-detect works on most files.
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Paste or drop a file
Plain text in, plain text out. Up to ~5 MB works fine in the browser.
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Pick the target format
Or use shift / scale to keep the format and adjust timing.
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Copy or download the result
The output is a clean text file ready to use.
使用例
SRT to WebVTT for an HTML5 video
You have an SRT from a video editor. The web player needs WebVTT. Drop the SRT, pick VTT, copy.
SRT: 1 00:00:00,000 --> 00:00:03,500 Hello world
結果： WEBVTT 00:00:00.000 --> 00:00:03.500 Hello world
Shift subtitles 500 ms later
Your audio and subtitles are out of sync. The audio leads the text by half a second. Use the shift tool to push every cue 500 ms later.
00:00:00,000 --> 00:00:01,500 First line
結果： After +500ms shift: 00:00:00,500 --> 00:00:02,000 First line
SRT to SUB at 23.976 fps
A video editor needs frame-numbered SUBs. Pick the target fps (23.976 for film, 25 for PAL, 29.97 for NTSC, 30 for web).
SRT: 1 00:00:00,000 --> 00:00:01,000 A
結果： At 23.976 fps: {0}{24}A
よくある質問
関連ガイド
How to Convert SRT to VTT or SUB (and Why You Might Need To)
A practical guide to subtitle formats: the differences between SRT, WebVTT, and MicroDVD SUB, the format compatibility matrix for common players, the timing-shift and FPS-scaling cases that come up when subtitles drift, and how to convert everything in your browser without uploading your file anywhere.
What Is an SRT File? (And How Do You Read a Subtitle File)
SRT is the most common subtitle format: numbered cues with start and end timestamps and the text to display. Learn the structure, why it has weird line breaks, how to convert SRT to VTT or SUB, and how to fix the three most common mistakes (off-by-one timing, encoding, and Windows line endings).
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Last reviewed: 2026-09-25