How to use AI to add subtitles to marketing videos?

The Short Version

AI subtitle generation has become the fastest way to add captions to marketing videos. Instead of manual transcription (which takes hours), AI tools transcribe audio, generate timed subtitles, and sync them to your video automatically. Most CMOs use these tools because they're faster, cheaper, and more accessible than hiring transcriptionists.

Why Subtitles Matter for Marketing Videos

Before diving into tools, understand why subtitles are critical:

• 85% of video views happen without sound (social media, offices, public spaces)
• Improves SEO — search engines can index subtitle text
• Increases engagement — viewers stay 80% longer with captions
• Accessibility requirement — WCAG compliance for legal protection
• Multilingual reach — AI can translate subtitles to expand audience

Step-by-Step Process

1. Choose Your AI Subtitle Tool

The best tool depends on your workflow:

• Descript — Best for marketing teams. Transcribes, edits, and exports in one platform. $24/month for unlimited transcription. Includes video editing, speaker identification, and filler word removal.

• Rev — Best for high accuracy. Human review available if needed. $0.25/minute for AI-only or $1.25/minute for human review. Fastest turnaround (minutes vs. hours).

• Kapwing — Best for social media. Built-in video editor, multiple subtitle styles, and direct export to TikTok/Instagram formats. $10-30/month.

• Submagic — Best for short-form content. Optimized for TikTok, Instagram Reels, YouTube Shorts. $10/month. Includes auto-framing and trending fonts.

• Adobe Premiere Pro (with Speech to Text) — Best if you already use Premiere. Native integration, $55/month Creative Cloud subscription. Accuracy is 90-95%.

2. Upload Your Video

Most tools accept:

• MP4, MOV, WebM, AVI formats
• File sizes up to 2-5GB (varies by platform)
• Direct uploads or cloud integration (Google Drive, Dropbox)

Processing time: 2-10 minutes depending on video length and platform load.

3. Review and Edit Transcription

AI accuracy ranges from 80-95% depending on:

• Audio quality — Clear audio = higher accuracy
• Background noise — Loud environments reduce accuracy
• Accents and technical terms — May require manual correction
• Multiple speakers — Some tools auto-identify speakers; others need manual labeling

Pro tip: Spend 5-10 minutes reviewing the transcript. Fix:

• Brand names and product terms
• Technical jargon
• Speaker names
• Timestamps (if syncing is off)

4. Customize Subtitle Style

Marketing-specific customizations:

• Font and size — Ensure readability on mobile (minimum 18pt)
• Color and background — High contrast for accessibility (white text on black background is standard)
• Positioning — Bottom center is default; adjust for logos or graphics
• Duration — Adjust reading speed (typically 2-3 seconds per subtitle)
• Language — Auto-translate to Spanish, French, German, Mandarin, etc.

5. Export and Integrate

Export options vary by tool:

• Burned-in subtitles — Subtitles embedded in video file (can't be turned off)
• SRT/VTT files — Separate subtitle files (viewers can toggle on/off)
• Direct platform export — YouTube, TikTok, Instagram-ready formats

Recommendation: Export as SRT files for maximum flexibility. You can use them across platforms and update later without re-rendering video.

Cost Comparison for Marketing Teams

| Tool | Price | Best For | Accuracy |

|------|-------|----------|----------|

| Descript | $24/mo | Unlimited transcription | 90% |

| Kapwing | $10-30/mo | Social media videos | 85% |

| Submagic | $10/mo | Short-form content | 88% |

| Rev | $0.25/min | High accuracy needs | 95%+ |

| Adobe Premiere | $55/mo | Existing users | 92% |

Pro Tips for Marketing Videos

• Test on mobile first — 70% of video views are mobile; subtitles must be readable
• Use speaker identification — Helps viewers follow conversations in interviews or testimonials
• Add branded fonts — Some tools (Kapwing, Submagic) let you match brand guidelines
• Create multiple versions — Burned-in for social, SRT files for YouTube (better for SEO)
• Batch process — If you produce 10+ videos/month, use tools with batch upload (Descript, Rev)
• Translate strategically — Focus on top 3-5 languages based on audience geography

Common Mistakes to Avoid

• Skipping the review step — AI errors compound across videos; always spot-check
• Using tiny fonts — Subtitles must be readable on phone screens (minimum 18pt)
• Forgetting accessibility — Use high contrast and avoid color-only differentiation
• Burning in subtitles permanently — Keep SRT files separate for flexibility
• Ignoring speaker identification — Unlabeled speakers confuse viewers in multi-person videos

Integration with Your Marketing Workflow

For CMOs managing video at scale:

1. Establish a template — Create standard subtitle styles in your chosen tool
2. Assign ownership — One person reviews all transcripts for brand consistency
3. Build a library — Save SRT files in cloud storage (Google Drive, Dropbox) for reuse
4. Measure impact — Track engagement metrics (watch time, shares) for subtitled vs. non-subtitled videos
5. Automate where possible — Use Zapier or Make to trigger subtitle generation when videos upload

Bottom Line

AI subtitle tools like Descript, Rev, and Kapwing can add professional captions to marketing videos in 2-5 minutes with 85-95% accuracy. Invest 5-10 minutes in review and editing, then export as SRT files for maximum flexibility across platforms. For teams producing 10+ videos monthly, Descript's unlimited transcription ($24/month) offers the best ROI. Always prioritize mobile readability and accessibility—subtitles aren't optional anymore; they're essential for engagement and compliance.