Step 1
Upload video
Upload your MP4 video file to Sonix and select the language.
Add subtitles to MP4 videos
Sonix automatically transcribes your MP4 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 MP4 in minutes
99%
Accuracy rate
Industry-leading AI transcription
53+
Languages
Subtitles in any language
Custom
Styling
Fonts, colors, positioning
Add subtitles to MP4 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 MP4 subtitles
Can Sonix add subtitles to MP4 videos?
Yes! Upload your MP4 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 MP4 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 MP4 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 MP4 files
Other MP4 conversions
Trusted by video creators
Amazing for foreign videos that need subtitles. The platform is super easy to use and gave me EXACTLY what I was looking for.
Sonix is simple and very easy to use and the results were very nearly perfect. I would definitely recommended the site to anyone who asks me.
I LOVE Sonix. It's saving my life. I'm working on a project with almost NO budget, interviewing a bunch of people and the Sonix transcriptions are accurate, and are so easy and int...
I loved that Sonix supports so many languages. I've been working on a project that involves speakers of 6 different languages and it allows me to translate everything into English ...
It really accelerated my work and I was amazed by the accuracy, especially given that the video featured only non-native speakers.
I tried Sonix for the first time and I was astonished by the incredibile conversion accuracy.
My transcript work flow is so fast now. It takes me half the time it used to. So glad i found you :)
Awesome and I was really shocked when I saw how carefully my mp3 file was transcribed!!
Add subtitles to MP4 now
Try Sonix free with 30 minutes of transcription. No credit card required.
