Free Word Timestamps to SRT and VTT Converter

Words to SRTMake SRT or WebVTT captions from word timestampsDrop a transcript with word times (OpenAI verbose_json, or a Sucia Studio transcript), choose how many words a caption holds, and download SRT or WebVTT.Free. Works in any browser, on a phone or a computer. What you put here stays on your device.About Words to SRTWhat it reads

OpenAI-style verbose_json: a JSON object with a words list, each word with word, start and end in seconds (what the transcription API returns with word timestamps on). The same words inside segments are read too.

A Sucia Studio transcript file: segments with words, each word with s, e and w in seconds; one chunk file or a list of them.

How the captions are cut

At most the number of words you choose a cue, 8 to start, and at most the seconds you choose, 3.5 to start.

A new cue after a pause of 0.7 seconds or at the end of a sentence; every cue stays up for at least 0.2 seconds.

The same rules Sucia Studio uses for its captions, from the same code.

How to use it

Drop the JSON file, or paste it. It is read on this device.

Set the words and seconds a cue; the preview changes as you do.

Download the SRT or the WebVTT and upload it in YouTube Studio (Subtitles), which takes both in plain UTF-8.

Rules as read on October 9, 2026 from YouTube Help: Supported subtitle and closed caption files.Questions

Where do I get word timestamps?

From OpenAI's transcription API with word timestamps on (verbose_json), from Whisper tools that write the same shape, or from Sucia Studio, which makes a transcript on your computer.

Why eight words a cue?

It is what reads well on a phone: two short lines, gone before the next thought. Set fewer for Shorts, more for a slow talk.

Can it fix the words?

No. Fix the text in the JSON first, or open the SRT it makes in Caption Check and fix the lines there.

Is my transcript uploaded?

No. It is read and converted in your browser.

SRT Converter: Convert caption files, and fix their timing

Caption Check: Check an SRT or VTT caption file

Have Sucia make the captions