Convert FLAC to captions

Create accessible closed captions from your lossless FLAC audio. Professional-quality captions from the highest quality source audio.

ADA compliant
5-min turnaround
Accessible
Audio
Video
DOCX
SRT/VTT
PDF
53+ Languages
About This Format

Understanding FLAC files

What is a FLAC file?

Lossless audio compression - CD quality at half the size

Free Lossless Audio Codec file (FLAC) is an audio format similar to MP3, but lossless. What does this mean? The audio in a FLAC file is compressed without any loss in quality, whereas a MP3 file compresses the audio but usually lowers the quality of the file by excluding certain frequencies. A FLAC file works similar to how a ZIP file is compressed. Since FLAC is highly optimized for audio, you’ll receive a better compression ratio when compared to the ZIP compression algorithms. You can play compressed FLAC files in your favorite media player (including VLC, your car, or home stereo, or computer) just like you would an MP3 file (without having to uncompress it separately).
FLAC files are one of the fastest and most widely supported lossless audio codecs and is one of the few that are non-proprietary and has a well-documented open-source reference implementation. There are no attached patents for FLAC files. It was developed in 2000 and FLAC files discourage developers to not include any DRM features.

Common Uses

  • Audiophile music collections
  • Music archiving
  • High-fidelity audio
  • Lossless music streaming

Audio Quality

Bit-perfect lossless compression - identical to original

Transcription Tips for FLAC

  • Excellent for transcription - no quality loss from compression
  • Smaller than WAV but same audio quality
  • Well-suited for interview and podcast archiving

Where FLAC Files Come From

  • Bandcamp downloads
  • HD music stores
  • Audio archivists
  • Tidal streaming rips
10x
Faster than real-time
Get your FLAC captions in minutes
99%
Accuracy rate
Industry-leading AI for FLAC files
53+
Languages
Captions in any language
30+
Export formats
SRT, VTT, SCC, and more
How It Works

Create captions from FLAC in 6 steps

Step 1

Create account

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

Step 2

Upload file

Upload your FLAC 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 FLAC with word-level timestamps.

Step 5

Edit captions

Fine-tune timing and formatting for accessibility.

Step 6

Export

Download closed captions in SRT, VTT, or SCC format.

Common Questions

Everything about FLAC captions

Why use FLAC for professional captions?

FLAC's lossless audio provides the clearest source for caption transcription. When accuracy is critical, FLAC source files deliver the best possible results.

Are FLAC-to-caption conversions ADA compliant?

Sonix generates captions meeting ADA requirements. FLAC's perfect quality helps achieve accuracy levels exceeding professional captioning standards.

Can I add sound descriptions to FLAC captions?

Yes! After transcription, add non-speech descriptions like [music], [applause], or [door closes] in Sonix's editor.

How accurate are AI captions from FLAC?

Sonix achieves 99%+ accuracy on clear FLAC audio, often exceeding this due to the pristine lossless quality.

What caption format works for broadcast FLAC?

For broadcast television, export to SCC or STL formats which meet FCC requirements.

Can I caption FLAC files with multiple speakers?

Yes! Speaker detection works excellently with FLAC's perfect audio quality. Each speaker gets labeled captions.

Why Sonix

Accessible captions from FLAC files

Accessibility First

Create captions that make your content accessible to deaf and hard-of-hearing viewers.

ADA Compliant

Meet accessibility requirements with properly formatted closed captions.

Sound Descriptions

Add non-speech elements like [music] and [applause] for full context.

SEO Benefits

Captions make video content searchable and improve discoverability.

Related

More ways to convert FLAC files

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Other file formats

OPUS to text
WMA to text
OGG to text
AIFF to text
M4A to text
AMR to text
WEBA to text
MP2 to text
MP3 to text
CAF to text
See all supported file formats
Reviews

Trusted by accessibility teams

4.98 rating from 211 reviews

Sonix's transcription and translation features are stunningly accurate, I'm very impressed.
CB
Constantine B.
Istanbul, Turkey
After trying a number of MP3 transcribers, I am most impressed with Sonix! It was easy to use and was much more accurate than any of the others that I tried.
SL
Stephen L.
Boca Raton, FL, USA
Transcription was almost perfect!!
DM
Diego M.
Granada, Spain
The highest accuracy I have ever achieved through similar services.
JB
John B.
Townsville, Australia
I heard about you from my friend. I found my transcription to be almost exactly what is in the audio file. Love it...continue what you are doing. Sonix is excellent. I appreciate t...
HG
Hardik G.
Ottawa, Canada
Very accurate transcription, ease of use and customer service. Price was also very reasonable.
FK
Feisal K.
Seattle, WA, USA
I tried several programs and Sonix was by far the best one.It gave me very accurate scripts
KA
Keti A.
Tbilisi, GA, USA
Easy to use and surprisingly accurate.
JB
Jon B.
Shakopee, MN, USA
Read more testimonials
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