Create accessible closed captions from your FLV videos. Bring legacy Flash content into accessibility compliance with professional captions.
Legacy Flash video format for web streaming
FLV files are also known as Flash Video Files. Most FLV files use Adobe Flash Player or Adobe Air to transmit audio/video over the Internet. Most embedded videos on the Internet are FLV files, but with the introduction of HTML5 videos, many streaming services have dropped usage of FLV files. You can sometimes see FLV files with a F4V file extension. FLV files aren’t as common now, but we still support them at Sonix.
Older format - quality varies significantly
Sign up for Sonix's free trial. Includes 30 minutes free.
Upload your FLV file from your computer or cloud storage.
Choose from 53+ languages spoken in your file.
Sonix AI transcribes your FLV with word-level timestamps.
Fine-tune timing and formatting for accessibility.
Download closed captions in SRT, VTT, or SCC format.
Captions include speaker identification and sound descriptions (music, applause, typing sounds) for deaf and hard-of-hearing viewers. Subtitles assume the viewer can hear and focus on translating dialogue.
Yes! Sonix generates captions meeting ADA and Section 508 requirements. Add speaker labels and sound descriptions to bring legacy Flash content into compliance.
Yes! After transcription, add non-speech descriptions like [music playing], [static noise], or [applause] in Sonix's editor for fully accessible captions.
Upload FLV, transcribe with Sonix, add speaker labels and sound descriptions, then export captions. Convert video to MP4 for modern accessible playback.
SRT is most universal for archival purposes. Include SRT files alongside your FLV archives (or converted MP4s) for accessibility.
Accuracy depends on audio quality, not file age. FLV files with clear speech transcribe at 99%+ accuracy. Lower-bitrate audio from early web videos may have slightly reduced accuracy.
Create captions that make your content accessible to deaf and hard-of-hearing viewers.
Meet accessibility requirements with properly formatted closed captions.
Add non-speech elements like [music] and [applause] for full context.
Captions make video content searchable and improve discoverability.
I am LOVING Sonix! The price, accuracy, create your own library, check marks when something is completed. I am so glad I found the service.
I was especially impressed with the quality when it comes to other accents as most other companies can only give a good machine transcript if it is a US accent. Sonix is amazing and I have nothing but good things to say. Thank you for providing this service!
Sonix is easy to use and high accuracy of the transcriptions. Very pleased!
The interface and editor experience were great. I also like the way you handle speaker identification and naming. Pretty slick. Nice timestamp frequency / formatting too.
I tried several programs and Sonix was by far the best one.It gave me very accurate scripts
I came across Sonix by accident... and boy was I glad I did. This tool is virtually word perfect and the SRT file it output worked perfectly...
I love how accurate the software is! The way you can play audio as you go through the text or click on any part of the text to hear the audio is amazing.
Sonix is easy to use. Ridiculously easy. And even though the accuracy wasn't perfect it saved several days in a typical transcription cycle and the hourly cost we usually pay.
Try Sonix free with 30 minutes of transcription. No credit card required.
AI transcription and translation in 53+ languages.
