Auto Captions for Video Free — AI Subtitle Generator

Captions are no longer optional. 85% of Facebook videos are watched without sound. Instagram Reels and TikTok videos with captions get significantly higher engagement. Accessibility laws require captions for many professional uses. But adding subtitles manually is tedious -- a 5-minute video can take 30+ minutes to caption by hand.

MiOffice auto-generates captions using Whisper AI running locally in your browser. Speech is transcribed to text, timed to the video, and burned directly into the video frames. No upload, no subscription, no per-minute charges.

How to Add Auto Captions

1. 1

   Open Auto Captions

   Go to the auto captions tool.

2. 2

   Customize Settings

   Upload your video (MP4, MOV, WebM, up to 200MB). Choose font size (18-40px) and position (top or bottom).

3. 3

   Download Captioned Video

   Whisper transcribes the audio, then FFmpeg burns the captions in. Download your captioned video.

Auto Captions vs Manual Subtitles

Why Captions Matter

• --Social media engagement: Captioned videos get 12% more views and 40% more engagement on average.
• --Accessibility: 466 million people worldwide have disabling hearing loss. Captions make content accessible.
• --SEO: Search engines cannot watch video but can index captions, improving discoverability.
• --Sound-off viewing: 85% of social media video is watched without sound. No captions means no message.

Privacy

The Whisper AI model runs entirely in your browser. Your video audio is never sent to any server for transcription. This makes MiOffice suitable for captioning confidential meetings, legal recordings, and private content.