Video captions generator: how to automatically add subtitles to any video

Captions aren't optional anymore. YouTube videos with captions get more watch time. Social media platforms auto-promote captioned content because silent autoplay viewing is dominant — 85% of Facebook videos are watched without sound. Accessibility requirements affect anyone publishing for public audiences.

The workflow that works: AI generates a draft in minutes, you review and correct it, then upload or burn it in.

Step 1: Generate the SRT file

Fastest method for YouTube: Upload your video to YouTube Studio. YouTube generates auto-captions within a few hours of upload. Go to YouTube Studio → your video → Subtitles → Edit to review and correct. Free, no extra tools.

For higher accuracy or non-YouTube platforms: Upload your video file to TranscribTxt Pro (SRT export requires Pro at $12/month). The SRT downloads with timestamps synced to your video.

A 10-minute video generates captions in about 1 minute. A 30-minute video takes 3 minutes.

Step 2: Review the SRT

Open the SRT file in any text editor. It looks like this:

1
00:00:01,000 --> 00:00:03,500
Welcome to today's video.

2
00:00:03,800 --> 00:00:07,200
We're going to cover three things.

Review for:

• Wrong words (especially names, brand names, technical terms)
• Timing issues where captions appear too early or late
• Missing punctuation that makes captions hard to read
• Long lines that need to be broken into shorter segments

A 10-minute video takes 15-20 minutes to review. This is much faster than writing captions from scratch.

Step 3: Add captions to your video

YouTube: YouTube Studio → Subtitles → Add → Upload file → select your SRT. The SRT replaces or supplements auto-captions.

TikTok: TikTok's editor accepts SRT files when uploading from desktop. On mobile, use TikTok's built-in auto-caption feature and edit manually.

Instagram Reels: Instagram doesn't support custom SRT upload. Use CapCut or another mobile editor to add captions from your SRT before uploading, or use Instagram's built-in auto-captions.

Burning captions into the video: If you need captions embedded in the video file (not as a separate subtitle layer), use DaVinci Resolve (free) or Premiere Pro. Import your video and SRT, and export with captions rendered into the video.

Platform-specific notes

YouTube is the most flexible — it accepts SRT, supports auto-captions, and lets you edit captions directly in Studio. The YouTube auto-caption accuracy has improved significantly with their ASR updates in 2024-2025.

TikTok has built-in auto-captions that work reasonably well for US English. For non-English content or higher accuracy, add captions in CapCut before uploading.

Instagram doesn't support external SRT upload directly. Burn captions into the video using a mobile editor.

LinkedIn supports SRT upload. Go to video settings after upload and add a subtitle file.

Facebook supports SRT upload in the post creation flow.

Getting better results

Record clear audio. Captions are only as good as the audio they're generated from. A lavalier mic clipped close to the speaker produces better auto-captions than a camera microphone 3 feet away.

Speak at a normal pace. Very fast speech (over 160 words per minute) causes more transcription errors and creates captions that display too quickly for viewers to read.

One speaker at a time. Auto-caption tools struggle when two people talk simultaneously. If you're producing an interview-style video, edit out crosstalk before generating captions.