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 54+ 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 53+ languages from your original video.
More ways to work with M4V files
Other M4V conversions
Trusted by video creators
Fantastic product and service. Fast, great quality transcript, great online editing facility. Whole experience was easy and problem free.
Easy to use and saved me mega amounts of time!
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 ...
I came across Sonix by accident... and boy was I glad I did. This tool is virtually word perfect and the SRT file it output worked perfectly...
I'm fully going to recommend Sonix to everyone! Most people are going to be blown away!
I had been using Dragon voice recognition software, but Sonix eliminates that step all together. I absolutely love Sonix.
Your product is incredible. I love it!
Way better than other transcription services I've tried. It will save me a lot of time. I'd recommend it to everyone I know.
Add subtitles to M4V now
Try Sonix free with 30 minutes of transcription. No credit card required.
