Transform your FLV videos into professional subtitles in multiple formats. Make legacy Flash content accessible and modern with professional subtitles.
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.
Customize line length, duration, and subtitle breaks.
Download subtitles as SRT, VTT, or other formats.
Sonix exports FLV transcriptions to all major subtitle formats: SRT (universal), VTT (web), ASS/SSA (styled), SBV (YouTube), and more.
SRT is most compatible when converting FLV to MP4 or other modern formats. Most video editors and players support SRT without issues.
Convert your FLV to MP4, export SRT from Sonix, then either upload the SRT separately to YouTube or burn subtitles into the video before uploading.
Yes! Export to ASS/SSA format for advanced styling options including custom fonts, colors, positioning, and animations.
Most social platforms require burned-in subtitles. Convert FLV to MP4, export SRT from Sonix, then use video editing software to embed them permanently.
Sonix timestamps are audio-based, ensuring accurate sync regardless of video encoding variations common in FLV files from different eras.
Export subtitles as SRT, VTT, FCPXML, and more for any platform.
Control line length, duration, and style of your subtitles.
Create subtitles in 53+ languages from your original audio.
Permanently embed subtitles into your video with one click.
I am VERY happy with the transcription! There were a few glitches, but 98% great.
The transcription was fast and accurate.
The level of accuracy and your UI is quite amazing. It allowed me to try the product without having to learn anything new, I was so happy about it I sent the results to a couple of...
I’ve been using your transcription software for about a year now. I just wanted to let you guys know that I think it is incredible. I have tried many alternatives, and none of them have bee...
I was surprised in the accuracy from the audio to script. Out of 3 transcripts, only one had to be adjusted. Perfect!!
I was amazed by your accuracy. What I used were not very good recordings. One with an American accent, another one Australian and many background noises. The transcript exc...
I LOVE Sonix. It's saving my life. I'm working on a project with almost NO budget, interviewing a bunch of people and the Sonix transcriptions are accurate, and are so easy and int...
I love how easy and intuitive it is to use Sonix! I can now put my energy and focus on actual content, instead of going through the tedious and time consuming process of transcribi...
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AI transcription and translation in 53+ languages.
