Generate a WebVTT caption file from any video or audio. AI transcribes and times each cue so you can upload the .vtt to your site, LMS or video player.
Free for recordings up to 1 hour and 1 GB. Longer files need a paid plan.
How It Works
Drop an audio or video file — MP4, MOV, MP3, WAV, M4A and more. The language is detected automatically.
AssemblyAI transcribes every word with exact timings — usually a fraction of the recording's length.
Copy the text or download SRT, VTT and TXT files.
The VTT File Generator is a free online tool from ShortsHero: webVTT captions for web players. AssemblyAI speech recognition does the work — a 5-minute recording usually comes back in under 30 seconds. It is free for files up to 1 hour with no watermark; longer recordings need a paid plan.
Free transcription covers files up to 1 hour. If your recording is longer, a paid plan lifts the limit — or trim it into parts and run each one.
Why Use This Tool
Every word carries its start and end time, so subtitles line up with the speech.
The formats YouTube, Premiere, Resolve, CapCut and every major player accept.
Filter the transcript on the page to find any word and jump to its timestamp.
Full recordings, not a one-minute sample. Paid plans lift the length limit.
The spoken language is detected automatically.
Use the files anywhere — the transcript and subtitles are yours.
Yes. Files up to 1 hour long are free, with no watermark and no account needed. Recordings longer than 1 hour need a paid ShortsHero plan.
MP4, MOV, WebM, MKV, MP3, WAV, M4A, AAC, OGG, FLAC and most other audio and video formats, up to 1 GB. For a long video, uploading just the audio is faster.
Yes. Download the SRT and open it in our free online SRT editor, or in any video editor, to fix a word or a timing.
Usually well under the length of the recording — a 10-minute file is typically done in about a minute.
ShortsHero turns long videos into short vertical clips with AI moment detection, face tracking and animated captions — and has free tools for subtitles, transcripts and video formats.
The same transcription powers ShortsHero's clip maker: it finds the strongest moments, reframes them to vertical and adds word-by-word captions in 36 styles.
Try the clip maker freeFree to start · No credit card required
Keep Going
Make an SRT with one word per cue. AI gives every word its own start and end time, perfect for punchy Premiere, CapCut or Resolve captions.
Shift SRT timing in one step. Enter how many seconds to move every subtitle earlier or later, preview the result and download the fixed file. Free, in browser.
Subtitles drifting further out of sync? Convert SRT timing between 23.976, 24, 25 and 30 fps so captions stay locked to speech from start to end.
Split an SRT file into parts at any timestamp, with timing reset for each part. Handy when you cut a long video into episodes or clips. Free and in browser.
Check every subtitle against reading-speed rules. See characters per second, line length and duration, with lines that break Netflix or BBC limits highlighted.
Validate an SRT file before upload. Finds overlapping cues, bad timestamps, missing numbers and blank lines, then fixes them in one click so YouTube accepts it.