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
Having tried numerous transcription services, this was undoubtedly the best. There were features (such as the synching up of the audio to the words for review) that I hadn’t ever hoped to find.
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 love Sonix.ai. They're fast and clean in transcription; they give 98% accuracy in your transcript. I enjoy every of my experience with Sonix...
I have to say the Arabic transcription was pretty awesome.
I’ve been using your transcription software for about a year now. I just wanted to let you guys know that I think it is incredible. I have tried many alternatives, and none of them have bee...
I have been a dialogue system researcher for half a decade now. I had build my own app for doing the transcriptions. Sonix was clearly better than what I had. I made the switch!
It's SO fast! I couldn't believe it. It's saved me hours of time.
I have a 30-40 minute commute to work and like to dictate memos and other brief documents along the way–but I haven't had an easy way to get them transcribed...until now. Thanks Sonix!
Add subtitles to M4V now
Try Sonix free with 30 minutes of transcription. No credit card required.
