Convert MP3 to subtitles

Transform your MP3 audio into professional subtitles in multiple formats. Sonix automatically generates accurate, timed subtitles ready for video, streaming platforms, or accessibility compliance.

SRT & VTT
5-min turnaround
All platforms
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 subtitles in minutes
99%
Accuracy rate
Industry-leading AI for MP3 files
53+
Languages
Subtitles in any language
30+
Export formats
SRT, VTT, FCPXML, and more
How It Works

Create subtitles from MP3 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 your MP3 with word-level timestamps.

Step 5

Split subtitles

Customize line length, duration, and subtitle breaks.

Step 6

Export

Download subtitles as SRT, VTT, or other formats.

Common Questions

Everything about MP3 subtitles

What subtitle formats can I export from MP3?

Sonix exports MP3 transcriptions to all major subtitle formats: SRT, VTT, ASS/SSA, SBV, STL, and more. Choose the format that matches your video editing software or streaming platform requirements.

How are subtitles timed from an audio-only MP3?

Sonix analyzes speech patterns during transcription to create precise word-level timestamps. These timestamps form the foundation for subtitle timing, ensuring each caption appears and disappears in sync with the spoken content.

Can I create subtitles for a podcast MP3?

Absolutely! Convert your podcast MP3 to subtitles for video versions, YouTube uploads, or social media clips. Sonix handles multi-speaker podcasts with speaker identification, so viewers know who's talking in each subtitle.

What's the best subtitle format for YouTube from MP3?

YouTube accepts SRT and SBV formats. We recommend SRT for MP3-to-subtitle conversions as it's widely supported and easy to edit. Upload the SRT file in YouTube Studio under your video's subtitle settings.

How do I improve subtitle accuracy from my MP3?

Start with clear, high-bitrate MP3 files (128kbps+). After transcription, use Sonix's editor to correct any errors before exporting subtitles. The editor shows audio waveforms so you can verify timing accuracy.

Can I hardcode subtitles onto video from my MP3 audio?

While Sonix generates subtitle files (soft subtitles), you'll need video editing software to burn them into the video (hard subtitles). Export your SRT from Sonix, then import it into your video editor and render with subtitles embedded.

Why Sonix

Professional subtitles from MP3 files

Multiple Formats

Export subtitles as SRT, VTT, FCPXML, and more for any platform.

Customizable

Control line length, duration, and style of your subtitles.

Translate

Create subtitles in 53+ languages from your original audio.

Burn-in Option

Permanently embed subtitles into your video with one click.

Reviews

Trusted by content creators

4.98 rating from 211 reviews

Sonix is by far the best transcription tool I have ever used.
MA
Mic A.
Ikeja, Nigeria
Excellent tool if you're looking for an accurate Turkish transcription. I tried a handful of ones, and Sonix won by a landslide.
AK
Ahdi K.
Ankara, Turkey
Your product is amazing, I love so many features including the video capture on the side, ability to change the transcript as you go, highlighting, downloading audio files... SEARC...
VN
Vera N.
Brooklyn, NY USA
I ran through your software and it is fantastic! For what we need it's a game-changer.
GW
Geoff W.
Sydney, NSW Australia
I loved how accurate you are even in Dutch!
GP
Gemma P.
East Falmount, MA, USA
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...
FV
Frank V.
Lagos, Nigeria
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