SRT ↔ WebVTT
字幕格式转换

Local browser processing. No upload. Subtitle text and filenames stay in this browser. / 浏览器本地处理，不上传字幕或文件名。

JavaScript and supported browser required / 需要 JavaScript 和受支持浏览器。

Supported format / 支持范围

UTF-8 only; maximum 1 MiB of UTF-8 text and 1,048,576 characters. No binary, NUL, replacement characters or unsupported controls. / 仅支持 UTF-8，不接受二进制或异常控制字符。

Text cues with increasing start times, start strictly before end; overlap allowed. Hours 00–99, minutes/seconds 00–59, exactly three millisecond digits. SRT requires sequential numbers from 1. WebVTT requires an exact WEBVTT header and blank line; identifiers must be absent or sequential numbers. / 起始时间不递减，结束晚于开始；可重叠。SRT 编号从 1 连续递增。

Reject unsupported WebVTT header metadata, NOTE, STYLE, REGION, cue settings, named identifiers, inline styling/voice/karaoke tags and unsupported entities. Literal &, <, > entities are decoded; literal characters are escaped for VTT output. No silent metadata removal. This is a limited text converter, not universal or lossless WebVTT conversion. / 不支持的元数据、样式、定位、命名标识等会被拒绝，不会静默丢弃；不保证通用无损转换。

Timing and text line breaks are retained; line endings become LF, numbering is sequential, and timestamps are normalized. No shift, translation, transcription, merging or compression. / 保留时间与文本换行，统一换行符、编号和时间格式；不提供偏移、翻译、转录或合并。