Convert VTT to SRT

Convert VTT to SRT only when the cues are representable

WebVTT can describe more than plain timed captions. A file may contain NOTE, STYLE, or REGION blocks, per-cue position and alignment settings, or timestamps embedded inside payload text. Standard SRT has no faithful general representation for those features. This converter stops when it finds them instead of silently deleting layout or metadata.

For representable cues, the job is precise: replace WebVTT timestamp periods with SRT commas, expand times to an hours field, add sequential cue numbers, and preserve each start, end, and payload line. A custom VTT cue identifier cannot occupy the SRT number slot, so it is replaced and the final receipt states how many identifiers changed.

Strict parsing prevents plausible damaged output

The source must be strict UTF-8 and begin with a valid WEBVTT header followed by a blank line. Every cue needs a valid timing separator, a positive duration, and payload. Unsupported X-TIMESTAMP-MAP and inline timestamp semantics are rejected. The parser reports the relevant line and column rather than extracting whatever resembles a time.

After writing SRT, the converter parses the whole result independently through the SRT path. It compares the cue count, integer-millisecond boundaries, and payload lines with the VTT source. Only a matching result becomes downloadable. This reopened-output check catches writer mistakes that a successful string replacement would miss.

Timing correction remains a separate job

Format conversion does not shift early captions, correct growing drift, translate text, or edit cue content. If the subtitles are out of sync, use the subtitle timing tool before or after conversion. If the destination accepts WebVTT, keeping the original may be better when the file uses VTT-only layout features.

Open a local .vtt file or paste its complete text. The preview may be clipped, but the download uses every verified byte and changes only the filename extension to .srt. No subtitle content, filename, timing, or output is uploaded or stored. For the opposite direction, use SRT to VTT.