Convierte transcripciones de reuniones en actas estructuradas con IA
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Use This ToolWhat is Convertidor de Subtítulos?
Convert subtitle files between SRT, VTT, and plain text formats. Adjust time offsets to fix sync issues, enforce per-line character limits for YouTube or broadcast standards, and convert character encoding between UTF-8 and Shift-JIS. Entirely browser-based — your subtitle files never leave your device.
Key Features
Convert SRT ↔ VTT ↔ plain text instantly
Time offset adjustment to fix sync issues (±seconds)
Per-line character limit enforcement (YouTube: 42 chars)
UTF-8 and Shift-JIS character encoding support
Paste text or upload .srt / .vtt / .txt files
Preview output before downloading
100% browser-based — files never leave your device
How It Works
1
Upload or Paste
Drop your subtitle file (.srt, .vtt, .txt) onto the page or paste the text directly into the editor.
2
Choose Options
Select the output format, set a time offset if needed, and optionally enforce a character-per-line limit.
3
Preview
Instantly preview the converted subtitle with timestamps and any applied transformations.
4
Download
Download the converted file in your chosen format, ready for YouTube, video editors, or broadcast software.
Who Is This For?
- ▸YouTubers converting audio transcription SRT output for upload
- ▸Video editors fixing subtitle sync after re-encoding
- ▸Broadcasters enforcing line-length standards
- ▸Translators working with subtitle files in different formats
- ▸Developers testing subtitle rendering in HTML5 video players
Why Use Convertidor de Subtítulos?
Online subtitle converters typically upload your files to a server and return the converted result. Zeraku's Subtitle Converter runs entirely in your browser — no upload, no waiting, instant results. It also goes beyond simple format conversion: time offset adjustment fixes sync issues that arise after video re-encoding, and the character-per-line limiter helps meet YouTube's 42-character recommendation or broadcast standards. Free, no account required.
Beginner's Guide
A subtitle file stores the text of spoken dialogue along with timestamps that tell the video player when to show each line. SRT (SubRip Text) is the most common format, used by YouTube and most video players. VTT (WebVTT) is the modern web standard used in HTML5 video. To convert a subtitle file: upload or paste your file, choose your target format, optionally adjust the timing or line length, then download. If your subtitles appear a few seconds early or late, use the time offset field to shift all timestamps at once.
Technical Details
Pure JavaScript implementation running entirely in the browser with no dependencies. SRT parsing uses a multi-line regex that matches the block number, timestamp range (HH:MM:SS,mmm --> HH:MM:SS,mmm), and text lines including multi-line cues. VTT parsing handles the WEBVTT header, optional NOTE and STYLE blocks, and cue identifiers. Timestamps are parsed to milliseconds for precise arithmetic during offset adjustment. Character limit enforcement inserts line breaks at word boundaries without splitting words. Character encoding conversion between UTF-8 and Shift-JIS uses the TextEncoder/TextDecoder API. Output is generated as a Blob and downloaded via an object URL, so files are never uploaded anywhere.
Frequently Asked Questions
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