Captions are no longer optional. Most short-form video is watched muted, accessibility matters, and on-screen text measurably lifts watch-time. The question is how to add captions to a video automatically — without typing them by hand or paying a per-minute cloud bill. Here’s how, including translated subtitles in another language.
Captions vs subtitles
The words get used interchangeably, but they solve different jobs:
- Captions — same-language text of the spoken audio, usually styled for short-form (word-by-word highlights, big bold fonts). The point is retention and accessibility.
- Subtitles — a translated text track in another language. The point is reaching a new-language audience.
Good tools do both. ViralMint handles same-language animated captions and translated subtitles from the same transcript.
How to add captions automatically (free)
The whole job is two steps: transcribe, then render. ViralMint runs both locally:
- Add your video — import a file or paste a URL (yt-dlp downloads it).
- Transcribe with Whisper — faster-whisper produces a word-level transcript on your machine, 90+ languages, no upload, no per-minute fee.
- Choose the output — word-by-word animated captions in a viral / classic / bold preset for shorts, or a plain SRT track.
- Export — captions burn in with exact word timing, or export the SRT. No watermark, any aspect ratio.
Because transcription runs on your own CPU, a 90-minute video costs the same to caption as a 5-minute one — there’s no minute cap to burn through. The captioning is part of the open-source clip extractor and Smart Video pipelines.
Why word-level timing matters
Cloud auto-captioners often drift a second or two off the audio. Whisper’s word-level timestamps mean each word highlights exactly as it’s spoken — the karaoke-style effect that makes viral captions feel tight. ViralMint renders these with the ASS subtitle format: three presets (viral yellow-highlight, classic bottom-aligned, bold green), customizable per channel. The same word timing also makes captions match an AI voice over perfectly when you narrate a faceless video.
Translated subtitles for a new-language audience
Captions in your own language grow retention; subtitles in another language grow your audience. Transcribe with Whisper, then translate. ViralMint’s translate & dub tool covers 19 target languages — including right-to-left scripts like Arabic — and can either burn in translated subtitles or generate a full AI voice dub. One source video becomes posts for several language markets.
Frequently asked
How do I add captions to a video automatically? Transcribe to text, then render the words timed to the audio. ViralMint runs Whisper locally and burns in animated word-by-word captions or exports an SRT — free, no watermark, no minute cap.
What’s the difference between captions and subtitles? Captions are usually same-language styled text; subtitles are a translated track. ViralMint does both.
Can I add subtitles in another language, like Arabic or Spanish? Yes — transcribe with Whisper (90+ languages), then translate and burn in or export. The translate-and-dub tool covers 19 languages including Arabic.
Caption your clips with the clip extractor, or translate a video with translate & dub.