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.
Free to start — no credit card required.See pricing
Auto-transcribe
Custom styling
Burn-in option
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.
Why won't my M4V file play on my computer?
Movies and TV shows purchased or rented from the iTunes Store often carry FairPlay DRM, which restricts playback to authorized Apple apps and devices. DRM-free M4V files play in most modern media players, including VLC.
Can I just rename an M4V file to MP4?
Often yes, because both extensions use the same MPEG-4 container, so renaming a DRM-free file usually works. Playback can still fail if the file uses AC-3 audio and the target player does not support that codec.
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
More ways to convert & transcribe
Jump straight to a related format, language, or tool — every link below is a real page.
Trusted by video creators
What I was able to do with Sonix was amazing. Transcribed and translated in minutes on remote Guatemalan WiFi!
Found you through Google. Super easy to use. Transcribed 98% correctly even though it was not a great audio file.
Add subtitles to M4V now
Try Sonix free with 30 minutes of transcription. No credit card required.
