Step 1
Upload video
Upload your M4V video file to Sonix and select the language.
Add subtitles to M4V videos
Sonix automatically transcribes your M4V video and lets you add professional subtitles with customizable styling.
Auto-transcribe
Custom styling
Burn-in option
Audio
Video
DOCX
SRT/VTT
PDF
53+ Languages
10x
Faster than real-time
Add subtitles to M4V in minutes
99%
Accuracy rate
Industry-leading AI transcription
53+
Languages
Subtitles in any language
Custom
Styling
Fonts, colors, positioning
Add subtitles to M4V in 4 steps
Step 2
Auto-transcribe
Sonix AI transcribes your video with word-level timestamps.
Step 3
Customize subtitles
Split subtitles, adjust timing, and customize fonts and colors.
Step 4
Export or burn-in
Download SRT/VTT files or burn subtitles directly into your video.
Everything about adding M4V subtitles
Can Sonix add subtitles to M4V videos?
Yes! Upload your M4V video, and Sonix will transcribe it and let you add professional subtitles with customizable styling.
Can I burn subtitles into the video?
Yes! Sonix can permanently embed (burn-in) subtitles into your M4V video with your choice of fonts, colors, and positioning.
What subtitle styles are available?
Customize fonts, colors, background boxes, positioning (top, center, bottom), and more for your burned-in subtitles.
Can I download subtitle files separately?
Yes! Export subtitles as SRT, VTT, or other formats to use with YouTube, Vimeo, or your video editor.
Can I translate subtitles to other languages?
Absolutely! Sonix can translate your subtitles into 55+ languages for multilingual videos.
How do I split subtitles correctly?
Sonix offers auto-split options for max characters per line, lines per caption, and max duration. Fine-tune manually if needed.
The easiest way to add video subtitles
Auto-Transcribe
Upload your M4V and get accurate subtitles automatically.
Custom Styling
Choose fonts, colors, and positioning for professional results.
Burn-in Option
Permanently embed subtitles into your video with one click.
Translate
Create subtitles in 54+ languages from your original video.
More ways to work with M4V files
Other M4V conversions
Trusted by video creators
I love how easy and intuitive it is to use Sonix! I can now put my energy and focus on actual content, instead of going through the tedious and time consuming process of transcribing audio.
I really like it. Easy to use, very accurate, and easy to correct when it is not. A truly super program, and I would recommend it to anyone.
The transcription was fast and accurate.
I tried 4 other services, and Sonix is the easiest to use, most accurate, and more reasonably priced for the quality.
The experience is fantastic, the system is easy to use, and transcription quality in different languages is unbeatable. Sonix is the best system I've tried so far...and I know one ...
Content is still king. Google can’t crawl audio from webinars and videos. Getting that content transcribed with Sonix is an absolute must if you want to drive more leads to your web site.
Seriously the best transcript I’ve ever seen. And the synchronized editor is amazing. I will be using again and I will be sharing with my friends :)
I was especially impressed with the quality when it comes to other accents as most other companies can only give a good machine transcript if it is a US accent. Sonix is amazing and I have ...
Add subtitles to M4V now
Try Sonix free with 30 minutes of transcription. No credit card required.
