How do I accurately convert my MP4 files to closed captions? 
Sonix uses the latest automated transcription technology to convert your video files (*.mp4) to closed captions. Follow these six steps and see how magical it is:
Step 1
Sign up for a free Sonix trial account—includes 30 minutes of free MP4 to captions conversion.
Step 2
Upload the MPEG-4 Video File file(s) (*.MP4) from your computer, Dropbox, Google Drive, or by dragging it on the page.
Step 3
Choose the language spoken in the uploaded MP4 file. We support over 38 different languages including Russian, Chinese, Spanish, and English. Click the 'Start Transcribing Now' button.
Step 4
Sonix will then automatically transcribe the audio from your MP4 file and convert it to a simple text format. Grab a cupcake, it will take only a few minutes.
Step 5
Use the Sonix AudioText Editor to polish your transcript before we convert it to a caption file. Simply type in your browser to correct any words in your transcript.
Step 6
Click the 'Export' button. Choose either 'Subrip subtitle file (.srt)' or 'WebVTT file (.vtt)' from the dropdown to download the closed caption version of your MP4 file. You can also adjust the character length and time duration length of each caption.
That's it! Your MP4 file has now been converted to closed captioning and is ready for the next step in your workflow!
Thousands of customers create closed captions from their MP4 files with Sonix 
Frequently Asked Questions for MPEG-4 Video File (*.MP4) to subtitle 
What is a MP4 file?
An MP4 file is also known as a MPEG-4 Part 14 multimedia container. MP4 files were developed by the Moving Picture Experts Group (MPED). WIth an MP4 File, there are separate compression algorithms for the audio and video tracks. Typically, video is compressed with the MPEG-4 codec and the audio is compressed using the AAC codec (which is the same codec used in AAC files). Most MP4 files are downloaded from Apple’s iTunes STore since most of the media downloaded from the store is downloaded in this format. The MP4 format is also used for Internet streaming video.
Does Sonix transcribe video files with a *.MP4 file extension?
Yes, Sonix does automatically transcribe video files with a .MP4 file extension. Sonix is an online video to text converter. Convert any audio (mp3, m4a, wav, ...) or video (mp4, mov, avi, ...) file to text without installing any software! Sonix quickly and accurately transcribes *.MP4 files and converts them to text in a subtitle format.
Know anyone who needs to convert MPEG-4 Video File (.MP4) to subtitle?
We'd appreciate it if you tell them about Sonix—the best way to convert MP4 to subtitle.
Other ways to convert your MP4 video files with Sonix
MP4 to text
Use the most accurate speech-to-text technology to convert files: MP4 to text.
MP4 to docx
Accurately transcribe your MP4 file to Microsoft Word Format (docx) so you can bring the transcript into your workflow.
MP4 to PDF
Easily transcribe your MP4 file to Adobe's Portable Document Format (pdf) so you can share them with colleagues.
MP4 to subtitles
Create subtitles for your MP4 files to make them more accessible for your audience.
MP4 to srt
Quickly create subtitles from your MP4 files and save them as SRTs, one of the most widely supported subtitle formats.
MP4 to VTT
Create more advanced captions for your MP4 files by using the latest caption format VTT (Video Text Tracks).
Add subtitles to MP4 files
Quickly and easily add subtitles to your MP4 video files with the power of automated transcription.
Create closed captions from your MPEG-4 Video File files with Sonix 
Sonix automatically transcribes and translates your audio and video files in over 38 languages. Easily search, edit, and share your media files. Sonix is an online, fully-automated speech to text service that quickly converts MPEG-4 Video File files to captions. Fast, accurate, and affordable. Millions of users from all over the world.
Includes 30 minutes of free transcription
