Convert FLV to WebM
Drop in an FLV and get a WebM back. WebM is the usual choice for HTML5 video where licence-free delivery is required. The practical difference is that the result opens anywhere, which FLV files do not. Your file never leaves your computer.
Need the other direction? Convert WebM to FLV
How to convert FLV to WebM
- 1 Drop your FLV .flv or .f4v file onto the page, or click to browse for it.
- 2 Set the quality, or leave the default, which keeps the file small without anything showing.
- 3 Convert. The work happens on your own machine, so how long it takes depends on your computer and the file.
- 4 Download the WebM, or add more files and do the whole set in one go.
Why convert FLV to WebM
- An FLV will not open in a browser, so anything going onto a web page, into a document or into a message has to become a WebM first.
- Completely royalty free.
- Noticeably smaller than MP4 at the same visual quality.
- HTML5 video where licence-free delivery is required.
- FLV: limited in what it can hold, with no modern features.
FLV compared with WebM
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | FLV | WebM |
|---|---|---|
| File extension | .flv | .webm |
| Transparency | No | Yes |
| Browser support | No browser support | All current browsers |
| Introduced | 2002 | 2010 |
| Developed by | Adobe / Macromedia | |
| Standard | Proprietary | Open |
Quality and what changes
Both formats are lossy, so this is a second generation of compression: the FLV is decoded back to pixels that already carry its artefacts, and WebM then compresses that. The damage compounds rather than cancelling out, which is why repeated round trips visibly degrade an image. Encode at a higher quality than the source used, and convert once from the best copy you have rather than from an already converted file.
- One WebM limitation to keep in mind: slower to produce than an MP4 of the same clip.
Questions about FLV to WebM
Will converting FLV to WebM lose quality?
A little. Both formats are lossy, so the file is decoded and compressed a second time and the two sets of artefacts add up. At a high quality setting the difference is hard to see, but avoid repeated round trips between lossy formats.
Is my FLV file uploaded anywhere?
No. The whole thing runs inside the browser tab you already have open. Your FLV is read straight from your own disk, converted on your machine and handed back as a WebM. Nothing is sent anywhere, nothing is stored and there is no account.
Is there a file size limit?
There is no server-side limit because no server sees the file. The real ceiling is your device memory, since the input and the output both have to fit in the tab. A few hundred megabytes is usually fine on a desktop machine and considerably less on a phone.
Can I convert several FLV files at once?
Yes. Add as many as you like and they are processed one after another, then offered as separate WebM downloads or as a single ZIP. Speed depends on your own processor rather than on a queue.
Does the converter work offline?
Yes, after the page has loaded once. The engine is cached by the browser, so you can disconnect, reload and keep converting. That falls out of doing the work locally rather than being a separate mode you switch on.