Convert MP3 to VTT

Create WebVTT caption files from your MP3 audio for HTML5 video players and web accessibility. Sonix generates standards-compliant VTT files with precise timing for seamless web integration.

HTML5 ready
5-min turnaround
Web compatible
Audio
Video
DOCX
SRT/VTT
PDF
53+ Languages
About This Format

Understanding MP3 files

What is a MP3 file?

Universal audio format supported everywhere

MP3 files are one of the most common audio file formats. Almost every player on any platform can open an mp3 file. The MP3 file format is a compressed file format with an intentional loss of audio quality. However, the loss should be negligible for the typical user. It was developed by the Moving Picture Experts Group (MPEG) and uses ‘Layer 3’ audio compression.
The audio compression preserves the audio within a normal human’s hearing range, while discarding unnecessary information outside of that range. MP3 files are usually used to store music and audiobooks with ‘near-CD quality sound’ (aka Stereo at 16-bit), but due to the great compression algorithm, the file size is around 1/10th of the WAV or AIF file equivalent. The quality of an MP3 file depends largely on the compression bit rate. Common bit rates are 128, 160, 192, and 256 kbps. And higher bit rates result in higher quality files that also require more disk space. MP3 files are easily handled and transcribed by Sonix, please try to upload higher bitrate quality audio files which will improve your transcript’s accuracy.

Common Uses

  • Music distribution
  • Podcast episodes
  • Audiobooks
  • Voice recordings
  • Music streaming

Audio Quality

Lossy compression; 192kbps+ indistinguishable from CD quality

Transcription Tips for MP3

  • 128kbps or higher recommended for accurate transcription
  • Very common format - Sonix handles all MP3 files
  • Variable bitrate (VBR) MP3s work fine
  • Avoid very low bitrates (below 96kbps) for speech

Where MP3 Files Come From

  • Spotify downloads
  • Podcast apps
  • Music players
  • Voice recorders
  • Web downloads
10x
Faster than real-time
Get your MP3 VTT in minutes
99%
Accuracy rate
Industry-leading AI for MP3 files
53+
Languages
Captions in any language
30+
Export formats
VTT, SRT, text, and more
How It Works

Convert MP3 to VTT in 6 steps

Step 1

Create account

Sign up for Sonix's free trial. Includes 30 minutes free.

Step 2

Upload file

Upload your MP3 file from your computer or cloud storage.

Step 3

Select language

Choose from 53+ languages spoken in your file.

Step 4

Auto-transcribe

Sonix AI transcribes and timestamps your MP3 audio.

Step 5

Edit captions

Fine-tune caption timing and text with our editor.

Step 6

Export VTT

Download your MP3 captions as a WebVTT file.

Common Questions

Everything about MP3 to VTT

What's the difference between VTT and SRT for MP3 captions?

VTT (WebVTT) is the modern web standard for HTML5 video captions, supporting styling and positioning that SRT lacks. If your MP3 audio will be used with HTML5 video on websites, VTT is the better choice. SRT is more universal for video editing software and older players.

Can I style VTT captions created from my MP3?

Yes! WebVTT supports CSS styling including fonts, colors, positioning, and backgrounds. While Sonix exports clean VTT files, you can add styling cues in any text editor. This lets you match captions to your brand's visual identity.

Are MP3-to-VTT captions accessible for screen readers?

VTT captions exported from Sonix follow accessibility best practices. They work with screen readers and assistive technologies when properly implemented with HTML5 video elements. This helps meet WCAG accessibility guidelines for media content.

How do I add VTT captions from MP3 to my website?

Add a <track> element to your HTML5 video pointing to your VTT file. Example: <track kind='captions' src='your-file.vtt' srclang='en'>. The browser handles the rest, displaying captions synchronized with your audio/video content.

Can I create multiple language VTT files from one MP3?

Yes! After transcribing your MP3, use Sonix's translation feature to create versions in 50+ languages. Export each translation as a separate VTT file, then offer viewers multiple caption language options on your website.

Do MP3-to-VTT captions work in all browsers?

WebVTT is supported in all modern browsers including Chrome, Firefox, Safari, and Edge. For older browsers, you may need a JavaScript polyfill. Native HTML5 video with VTT tracks provides the most reliable cross-browser caption experience.

Why Sonix

Web-ready VTT from MP3 files

HTML5 Native

VTT is the web standard for captions, supported by all modern browsers.

Styleable

Apply CSS styling for colors, fonts, positioning, and more.

Precise Timing

Word-level timestamps ensure perfect sync with your video.

Universal Support

Works with all HTML5 video players and web platforms.

Reviews

Trusted by web developers

4.98 rating from 211 reviews

I tried 3 other tools online and I can say that sonix blows them out of the water. I was very impressed with the ease of use, the % of words correctly translated and how simple it ...
MB
Maria B.
Peoria, AZ USA
We love transcribing with Sonix. Your interface for subtitle editing is excellent.
MG
Manuel G.
Madrid, Spain
Very high quality transcription - very accurate - only took a quick scan/sweep to manually correct/clean up the text.
NH
Nick H.
Wednesbury, UK
The accuracy of the initial transcription was better than any I've used to date, and making adjustments was very simple.
RM
Russ M.
Edmonton, Canada
I was amazed at how accurate Sonix is.
RM
Rocio M.
Pharr, TX USA
Gobsmackingly amazing! As a software developer of 40 years I know quality when I see it. An amazing product and a pretty damn good web-site to back it all up also. Totally ...
PZ
Paul Z.
Schaffhausen, Switzerland
Get Started

Create MP3 VTT captions now

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