Rescue an old Flash Video file (.flv) as a playable MP4 locally - usually losslessly, otherwise automatically re-encoded. No upload.
Running locally on your device ...
Running locally on your device ...
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Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
FLV was the dominant web video format of the 2000s and early 2010s - delivered via Adobe Flash Player, including by the original YouTube and countless downloader tools. Flash was officially discontinued in early 2021, and no current browser or plugin plays it anymore - a leftover .flv file is therefore effectively orphaned, even though its picture and sound are completely intact.
Honest distinction: newer FLV files (roughly from the mid-2000s, once Flash video moved to H.264) already carry H.264 picture and AAC audio - the conversion is then a pure, lossless repackage in seconds. Older FLV files instead use Sorenson Spark (from the H.263 family) or VP6, codecs no current browser or hardware can decode anymore - for those, the tool automatically performs a full re-encode instead of letting the file fail.
Either way you get a working MP4 - just not always equally fast. Everything runs locally in the browser, with your file never uploaded.
| Input formats | FLV |
|---|---|
| Output format | MP4 |
| Batch processing | No |
| Processing | Locally in your browser (WebCodecs) |
| File upload | None |
Limitations: If the FLV already carries H.264/AAC (the usual case for newer files), the conversion is lossless and finishes in seconds. With an older Sorenson/VP6 codec, the tool automatically performs a full re-encode - frame by frame in your browser, which can take several minutes for longer clips. One file per run, ~1 GB limit (4 GB/tab in the browser).
No, the entire conversion happens locally in your browser.
Adobe Flash Player was discontinued in early 2021 - no current browser plays FLV natively anymore, even though the file's content is completely intact.
For newer H.264 FLV files, yes, in seconds. For older Sorenson/VP6 files, the automatic re-encode takes longer.
During a lossless repackage, no. If a re-encode is needed, there is a small but normal amount of quality loss.
Yes, as long as it is a genuine .flv file - the tool detects and handles both codec generations automatically.