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.
You saved me! I got everything done in three days and I was sure it will take me a month.
I have tested your product among others, and I have to say, Sonix provides the best results, a really great product!!!
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...
It's incredibly fast, and it sets the timing for subtitles perfectly. I dread having to time everything myself, and with Sonix I can do that just by pressing Enter!
The accuracy of the initial transcription was better than any I've used to date, and making adjustments was very simple.
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 ...
I loved that Sonix supports so many languages. I've been working on a project that involves speakers of 6 different languages and it allows me to translate everything into English ...
Very cool and fascinating too. Ahh the power of algorithms. I can tell you that I love the overall UI experience because it's pretty, dumbed down, and very easy for me to use. I've...
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AI transcription and translation in 53+ languages.
