Generate subtitles from any audio or video
Upload a recording, get correctly timed captions — edit the text first, then export SRT or VTT that drops into YouTube, Premiere or CapCut.
By Anubhav Jain, Trustample founder · Updated July 2026 · Claims verified against the live product
Free: 60 min per 30 days, files up to 30 min / 50 MB · Paid plans: 10 to 100 hrs, files up to 2 GB. Big video? Upload just its audio track — same transcript, much faster upload.
Encrypted in transit · audio & video auto-delete in 30 days · never used to train AI
Optional settings
Set this for the most accurate result on quiet or mixed audio.
Get a second copy translated into another language (Pro).
Uncommon words the AI might misspell — list them so they come out right.
A subtitle generator does two jobs in one pass: it transcribes the speech, and it keeps the exact time each word was said. Those word-level timestamps are what turn a transcript into caption cues — numbered blocks with start and end times that video platforms and editors read natively. Trustample generates both standard formats: SRT (the universal one) and VTT (the web-native one).
The step most subtitle tools skip is the one that matters: editing before export. Captions burn mistakes into the screen, so a name misheard once appears misheard every time it's spoken. Here the transcript arrives in a synced editor first — click any line to hear that exact moment, fix the text, and the corrected version is what your SRT or VTT carries. The timing survives your edits untouched.
The honest version of "free": transcription starts free (60 minutes a month, TXT export), but subtitle file exports — SRT and VTT — are part of the paid plans, from Basic at $12/month. If you already have a subtitle file and just need to convert or check it, our standalone subtitle utilities (SRT to VTT, VTT to SRT, a caption line-length counter) are free with no signup at all.
How it works
- 1Upload the video or audio — MP4, MOV, MP3, anything common.
- 2Review the transcript in the synced editor; fix names and unclear lines.
- 3Export SRT or VTT — timed, numbered and ready for your platform.
Frequently Asked Questions (FAQs)
SRT or VTT — which one do I need?
SRT for video editors and most platforms (YouTube, Premiere, DaVinci Resolve, CapCut, VLC all accept it); VTT for web video players and HTML5 embeds. The content is nearly identical — if you're unsure, export SRT, and convert either direction with our free utilities anytime.
Will the subtitles be timed correctly?
Yes — timing comes from word-level timestamps recorded during transcription, not from guessing line lengths afterwards. Cues start when the speech actually starts. If you edit the text, the timing holds.
How long can a subtitle line be?
The industry guideline is 42 characters per line — beyond that, viewers can't read the caption at a glance. Our free subtitle character counter checks an existing file against that rule line by line.
How do I add the subtitles to a YouTube video?
YouTube Studio → your video → Subtitles → Add → Upload file → choose the SRT. YouTube pairs it with the video's audio automatically. The same file works if you later post the video elsewhere — that's the point of a standard format.
Can it generate translated subtitles?
The transcript can be translated (Pro translates on upload or afterwards, storing both languages), and the original-language subtitles export as SRT/VTT. A translated SRT export is on our list but not shipped yet — we'd rather tell you now than surprise you at the export menu.
Is there a watermark or a length limit?
Subtitle files export clean — no watermark in your SRT or VTT, ever. (Free-plan TXT exports carry a one-line credit; paid exports don't.) Length follows your plan: files up to 30 minutes free, 3 hours on Basic, 6 hr 40 min or 2 GB on Pro — with SRT/VTT export from Basic up.
An honest note: Automatic caption timing is only as good as the speech itself: overlapping speakers and long silences can produce cues you'll want to nudge in your video editor. For broadcast-grade work, treat the export as a very strong first draft, not a legal-compliance deliverable.
Related tools
Time-coded captions from any audio file — edit first, export clean SRT or VTT.
Video to TextA video transcriber for lectures, interviews, webinars and screen recordings — extract every spoken word as searchable, editable text.
MP4 to TextDrop in a video — we pull out the speech and hand you an editable transcript with timestamps.
See all converters on the transcription tools page.
Browse all transcription tools.