Building AI Caption Generator: Captions for Any Video in Seconds
By Anuj Ror · · 4 min read
Anyone who makes reels, shorts or YouTube videos knows the boring part. The video is done, but now you have to sit and type every word as subtitles, line by line, and fix the timing again and again.
That can take longer than editing the video itself. So I started building AI Caption Generator: upload a video, and the captions are written, timed and styled for you.
The idea
Most people watch short videos on mute. Without captions, half your audience scrolls past before hearing a single word. Captions are not optional anymore, but making them should not take hours.
The goal is simple: captions in seconds, not hours.
How it works, in simple words
First, the audio is pulled out of the video. Then Deepgram listens to it and turns the speech into text, along with the exact time each word is spoken. That timing is what makes the captions line up with the voice.
Next, OpenAI helps clean up the text, split it into short readable lines, and translate it when you want subtitles in another language.
Finally, FFmpeg renders the captions onto the video, or exports them as an SRT file if you want to add them yourself in an editor.
What it can do
- Auto captions for any video in seconds
- Subtitles in multiple languages
- Custom styles, colors and fonts
- Burn the captions into the video, or export an SRT file
- Batch processing for multiple videos at once
The tricky parts
Timing is harder than it looks. A caption that shows up half a second late feels wrong, even if every word is correct. Splitting lines at natural pauses, instead of in the middle of a phrase, also makes a big difference in how easy captions are to read.
Styling matters too. Short-form videos need big, bold captions that are easy to read on a phone, while tutorials need something calmer. That is why styles are fully customisable.
Good captions are not just correct. They are easy to read at a glance.
Where it is today
AI Caption Generator is still in development. The core flow works, and I keep improving accuracy, styles and speed. I will share updates here as it gets closer to launch.
Topics: AI caption generator, auto caption generator, video caption generator, subtitle generator, Hindi caption generator, captions in any language, AI subtitles, video captions online, AI, Captions, Subtitles, Video Tool, Multilingual, Web App, Anuj Ror
