Convert FLV to AVI Flash Video ↔ Audio Video Interleave Free Online Secure
Your FLV is opened here in your browser and its picture and sound are moved into an AVI container. When AVI accepts what was inside — which it usually does — nothing is re-encoded, so nothing is lost and it takes seconds.
Convert your file
Drop an FLV here, or choose one.
Your file never leaves this device. Everything runs in your browser.
Nothing uploaded
Where these formats come from
AVI is Microsoft's container from 1992, built when video was something you played from a CD-ROM. MOV is Apple's, a year older, and it was so well designed that the MP4 format the whole world now uses was built directly on it. FLV was Macromedia's, later Adobe's: it carried almost all internet video for a decade and disappeared with Flash at the end of 2020. The word that matters here is container. None of these three is a way of compressing video; each is a box that holds video compressed by something else, alongside the sound and the subtitles. That distinction explains most of the surprises on this page.
Where you meet them
AVI survives in old camera footage, in archives and in software that was written in the nineties and never replaced. MOV comes out of iPhones and Macs and is the working format of a great deal of video editing. FLV is almost entirely a legacy: files downloaded or recorded before 2020 that nothing modern will open. Converting between them is usually about making an old recording playable again, or handing a file to a program that insists on one particular box.
Questions people ask
What is the difference between a container and a codec?
The container is the box — AVI, MOV, MP4 — and the codec is how the pictures inside were compressed — H.264, MPEG-4, and others. A file called .avi tells you almost nothing about what is inside it. This is why one AVI plays and another does not, although both have the same extension: the player understands the box but not the codec within. It is also why converting between containers is sometimes instant and sometimes slow — in the first case only the box is being changed.
Why won't my old FLV files play any more?
Because the software that played them was Flash, and Flash was switched off at the end of 2020 and removed from every browser. The files themselves are intact; what has gone is the thing that knew how to open them. Converting to a modern container is the way to get them back, and it is worth doing before the tools that still understand FLV become scarce as well.
Does the file lose quality?
It depends on what the two formats can hold. Converting between formats that store the same thing — a PNG to a BMP, a WAV to a FLAC — loses nothing. Converting into a format that throws information away to save space, such as JPEG or MP3, loses a little every time, and converting back does not bring it back. Where a choice exists, this page errs towards keeping the original quality rather than making the smallest file.
Is my file uploaded anywhere?
No. The conversion happens inside your browser, on your own machine; the file never leaves it and there is no server here that could receive it. That is why a large file is limited by your own memory rather than by an upload, and why nothing you convert can appear in anybody's logs — including ours. The audio and video tools do fetch their conversion engine from this site the first time you use them, some thirty megabytes once; after that the work still happens entirely on your machine.
Why people convert FLV to AVI
FLV is the format of the Flash era: clips downloaded from old video sites, recordings saved from long-gone platforms, home videos exported by software that has since disappeared. Flash was retired in 2020, and with it went most of the places that could play FLV. Many players now refuse these files, and many editors will not import them. AVI, by contrast, is one of the most widely read video formats ever made, and almost every player, editor and device can open it. That is why people convert FLV to AVI: they have an old video that has stopped playing and they want it back in a form that works.
The situations are everyday ones. An old clip you downloaded years ago that your current player will not open. A family video saved in a format that your video editor rejects. A recording to be played on a television or a projector that reads AVI from a stick. A video to archive in a format that is more likely to survive. In each case the picture and sound are fine, and the wrapper is the problem. Converting FLV to AVI changes the wrapper.
This page converts FLV to AVI in your browser. Your video is not uploaded to a server, which matters for family footage and anything private. Below you will find how the conversion works, why it is often so fast, when it is not, and what to know about the converter itself.
How the conversion works
The container is rewritten, not the video
A video file has two layers. Inside are the picture and the sound, each stored in a particular coded form. Around them is a container, such as FLV or AVI, which holds the two together and tells a player how to play them. Here, your FLV is opened in your browser and its picture and sound are moved into an AVI container. When AVI accepts what was inside, which it usually does, nothing is re-encoded. That means nothing is lost, and the whole job takes seconds, however long the video is.
Why it is so fast
Because nothing needs to be re-encoded, the work is little more than copying. Re-encoding a film is slow and demanding; copying it into a new container is quick. A video an hour long can be moved in the time it takes to read this paragraph, because the converter is not touching the pictures, only the packaging.
What "container" and "codec" mean
A codec is the method used to compress the picture or the sound. A container is the file format that holds them. Changing the container without changing the codecs is like moving the contents of a box into a different box: the contents are identical, only the box is different. That is what makes the process lossless.
What is kept
The picture and the sound exactly as they were
When you convert FLV to AVI here, the picture and the sound are kept exactly as they were, whenever the destination accepts them. The video is not recompressed, softened or resized. What you see in the AVI is what was in the FLV, frame for frame.
Length, frame size and frame rate
The length of the film, the size of its picture and its frame rate are untouched. A clip of three minutes stays three minutes, a picture of 640 by 360 stays 640 by 360, and the speed of movement stays the same. Nothing is cut, stretched or sped up.
What may cost you something
When AVI will not take what the FLV held
Sometimes AVI will not accept the coded form of the picture or the sound that the FLV contains. In that case, the video has to be re-encoded, which means decoded and compressed again in a form AVI accepts. Re-encoding always costs a little quality, because compressing discards some detail. It also takes longer than simply moving the contents. The converter handles this automatically, but it is worth knowing why some conversions take seconds and others minutes.
Subtitles and chapter marks
Subtitles and chapter marks are not carried over. If your video has subtitles stored inside it, or markers that divide it into chapters, the AVI will have the picture and sound but not those extras. Old Flash clips seldom have them, but if yours does, keep the original and note what is missing.
The converter itself is fetched once
One practical point: the converter itself is not part of the page. It is fetched the first time you use one of these video pages, about nine megabytes, once. After that it stays in your browser, and later conversions start straight away. On a slow connection, the first use takes longer; offline, you need to have loaded it once before.
Long films on phones
Everything runs on your own device, so a long film on a phone may run out of memory before it finishes. If that happens, try on a computer, or cut the video into shorter parts first. On an ordinary computer, the problem appears only with very large files.
What FLV and AVI are
FLV, Flash Video, was the container of the video web for more than a decade. Sites such as early video portals, online lessons and news clips streamed FLV through the Flash player in the browser. When Flash was withdrawn in 2020, browsers stopped playing it, and software makers stopped caring about the format. Files saved from that era still exist in millions of archives, but fewer and fewer programs open them. AVI, Audio Video Interleave, goes back to the early 1990s and is one of the oldest and best-supported containers: virtually every player, editor and device can handle it.
When you convert FLV to AVI, you move a video from a container that has lost its home to one that is welcome almost everywhere. The picture and the sound inside do not need to change, which is why the job is usually so quick and lossless. That is the great virtue of the approach: it preserves what you have and only changes how it is wrapped.
Why Flash clips need rescuing
Videos from the Flash era are often the only copies of things that no longer exist online: a lecture, a local news clip, a family event uploaded to a site that closed. Because the format is dead, the longer you wait, the harder it becomes to open them. Moving them into AVI now, while the files still open, is a sensible form of insurance.
Old downloads and family videos
Many people have folders of FLV files they saved years ago and never opened again. Others have home videos exported from old software that wrote FLV. If you have such files, it is worth testing one: try to play it in your current player. If it plays, you may not need to do anything yet. If it does not, convert FLV to AVI and check that the result plays, then convert the rest of the folder in the same way.
Keep the originals until you are sure the AVIs are good, and keep them afterwards in an archive folder if you can spare the space. The AVI is a convenience copy; the FLV is the original. If a future program offers a better way of reading FLV, you will still have the source.
Naming and organising
Old downloads often have meaningless names, a string of digits or a title in a language you do not read. When you convert FLV to AVI, take a moment to rename the file so that it describes the video and the date. A folder of clearly named AVIs is far easier to search than a heap of FLVs with cryptic names.
Editing and presenting old clips
Video editors vary in what they import, and few accept FLV any more. If you want to include an old clip in a new project, such as a family compilation, a presentation or a documentary, converting FLV to AVI is usually the quickest route into the editor. Because the picture and sound are normally untouched, there is no quality cost, and the clip behaves like any other in the timeline.
For presentations, remember that some slide programs play AVI directly but not FLV. A clip that was impossible to embed in a talk becomes straightforward once it has been converted, although it is wise to test it on the machine you will present from, since codecs vary between computers.
Checking the codec on the target machine
An AVI file can hold different codecs inside, and a player needs to know the one it holds. If a converted file plays on your computer but not on another, the second machine may lack the codec. Playing it with a widely used player usually settles the matter, because such players carry their own codecs.
How to convert FLV to AVI here
Add your video
Drop the FLV onto the page or pick it from your device. It is opened inside your browser and is not uploaded.
Let it finish
Press the button. If the contents can simply be moved, it takes seconds. If they must be re-encoded, it takes longer. Leave the page open until it is done and do not switch to other apps, so the work is not interrupted.
Download and check
Download the AVI and open it in the player or editor you need it for. Watch the beginning, a bit from the middle and the end. Check that the sound is in step with the picture and that the length is the same as the original.
Questions people ask before converting
Will the quality drop?
Usually not. When AVI accepts what the FLV held, nothing is re-encoded, so nothing is lost. If re-encoding is needed, a little quality is given up.
Why did it take only a few seconds?
Because only the container was rewritten, not the video itself.
Will my television play the AVI?
AVI is widely supported, but a television reads AVI files with particular codecs inside. If the FLV held a codec the television does not know, it may not play. Try a short clip first.
Is my video uploaded?
No. Everything runs in your browser and the video never leaves your device.
Who converts FLV to AVI
People with old downloads and archives
Clips saved in the Flash era are moved into a format that today's players still open.
Video editors
An editor that rejects FLV will usually accept AVI, so a clip can go into a project.
Owners of televisions and projectors
Many devices read AVI from a stick and nothing else, so converting makes the clip playable.
Common mistakes
Deleting the original
Keep the FLV until you have checked the AVI on the equipment that matters.
Converting in chains
Each re-encode costs quality. Convert once from the original.
Closing the page too soon
A long film takes time. Leave the page open until the download is ready.
Related tools
To go the other way, convert AVI to FLV, though FLV is a dead format and best avoided. For Apple's format, FLV to MOV, AVI to MOV and MOV to AVI work in the same way, and MOV to FLV covers the last pairing. For the sound alone, WAV to MP3 and M4A to MP3 change the audio format.
When to convert FLV to AVI, and when not to
Converting is right when an FLV will not open where you need it: a player, an editor, a television or a projector. It is the wrong move when your current player opens the FLV perfectly well and you have no need to move it, and it is not the right tool if you want a modern, efficient format: AVI is old and widely supported, but not compact.
For the common cases, such as old downloads, family clips and files for editors and devices, it is quick, private and dependable to convert FLV to AVI in the browser. Your original is never changed, so you can come back and convert FLV to AVI again whenever you like.
Batches of videos
If you have many clips to convert, do them one at a time and keep the originals in a separate folder. Try one first and check it in the player or editor you will use, so you do not have to redo twenty of them. When you convert FLV to AVI in bulk, consistency matters more than speed.
If a file takes a long time
A conversion that takes minutes, not seconds, means the video is being re-encoded because AVI would not take what the FLV held. That is normal. Leave the page open and let it finish. Watch the result carefully afterwards, since re-encoding costs a little quality, and compare it with the original on a few scenes with fast movement or fine detail.
Checking the result properly
After you convert FLV to AVI, play the AVI from the beginning, jump to the middle and watch the end. Check that sound and picture stay together, that the length is the same and that the picture looks as it did. If everything looks right, the job is done; if not, the original is untouched, so you can try again or look for another route.
A simple routine to convert FLV to AVI well
Test whether the FLV still plays in your current player. If not, convert FLV to AVI, one clip first. Play the result in the program or on the device you will use. If it works, convert the rest and rename the files clearly. Keep the FLV originals in an archive folder. If you only want the soundtrack of a clip, extract it separately and use MP3 to WAV or FLAC to MP3 to bring it into the format you need. This routine takes a few minutes for a handful of clips, and it works whether you convert FLV to AVI once a year or every week.
Your video stays on your device
The conversion happens locally. Your video is opened by your own browser, moved into a new container there and handed back. Nothing is uploaded, so there is no copy on a server and no one else who could watch it. For family footage and private recordings, that is the safe way to convert FLV to AVI.
A worked example
Say you have a clip of 80 megabytes from 2009, saved as FLV, and your current player will not open it. You drop it here and press the button. In a few seconds you download an AVI of about the same size, with the same length, picture and sound. You open it in your player, and it plays. Nothing was re-encoded, so nothing was lost. The FLV stays in your archive folder.
Before you close the page
Check that you downloaded the AVI, that it plays in the program or on the device where you need it, and that you kept the original FLV.
Summary
To convert FLV to AVI here, drop the video and press the button. The picture and sound are moved into an AVI container, and when AVI accepts what was inside, which it usually does, nothing is re-encoded, so nothing is lost and it takes seconds. Length, frame size and frame rate are untouched. Where AVI will not take what the FLV held, the video is re-encoded, which costs a little quality. The converter is fetched the first time, about nine megabytes, once. Nothing leaves your device.