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AVI to FLAC Converter

Turn AVI files into FLAC in a couple of clicks. AVI is a legacy Microsoft container; FLAC is losslessly compressed audio — CD quality at roughly half the size. Some detail is discarded to fit the target format; how much depends on the format and your settings.

Not uploaded to any serverConverted on this deviceGone when you close the tabHow this works

Drop your files here

AVI files (.avi) · up to 512 MB each

or paste files from your clipboard

Ready when you are

Drop a AVI file above and FileTools360 will turn it into FLAC — right here on your device, without uploading anything.

⌘K to search converters

How to use it

1
Add your AVI files
Drag them onto the drop area, choose them from your device, or paste them from your clipboard. You can queue several at once. Nothing is sent anywhere — the file stays on this device.
2
Adjust the settings if you want to
The defaults suit most people. Open Advanced to control bitrate, sample rate and channels.
3
Convert and download
Press Convert. Everything happens on your own device — nothing is uploaded. Download files one by one, or grab them all as a ZIP.

Privacy, in plain words

Is it safe? Your AVI file is not uploaded anywhere

What “uploaded” normally means. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website. That copy is what the word “upload” means, and it is the part nobody explains.

What happens instead. This site does not do it. There is no server here that receives files, so your AVI file is read, converted and handed back by the browser you are using right now. It never travels — so there is no copy to store, read, leak or hand over.

Check it yourself in ten seconds

Turn off your Wi-Fi after this page has loaded, then convert a file anyway. It still works, because everything needed is already on your device.

The longer explanation of how this works, and the full detail of what is and is not stored on the privacy page.

Why this matters more than it sounds

Video is the format where the thing being converted is usually a recording of people, and often of people who did not expect a third party to have a copy. It matters more than it sounds, because of what video files usually are:

Security-camera footage

your home or premises, and who was in it

Family videos

children, addresses, the inside of your house

Medical or therapy consultations

clinical recordings under strict handling rules

Unreleased footage

material under embargo or still being edited

A file that is never sent cannot be kept, leaked, subpoenaed or used to train anything. That is a property of how this works, not a promise about how carefully it is run.

AVI and FLAC explained

AVI is a Microsoft container from 1992. It predates modern video compression and lacks features taken for granted today, such as proper support for variable frame rates and modern codec metadata.

FLAC compresses audio losslessly, typically to about half the size of WAV. Decompressed, it is bit-for-bit identical to the original — the compression is mathematical, not perceptual.

Where AVI files come from: Old camcorders, legacy Windows software and archived downloads.
Where FLAC is used: Hi-fi music libraries and archival rips of physical media.

AVI vs FLAC

The two formats solve different problems, which is why converting between them involves trade-offs rather than a straight upgrade.

AVI compared with FLAC
Property	Source	Target
Compression	Container (depends on codec)	Lossless
Animation	Yes	—
Introduced	1992	2001
Browser support	Wide but dated. Not supported in browsers.	Great on desktop and Android; iOS support is newer.

AVI is stronger at: Readable by very old software. Simple, well understood structure.
FLAC is stronger at: Lossless — provably identical to the source. Roughly half the size of WAV. Rich metadata and cover art support.

Why convert AVI to FLAC?

This is not really a format swap — it is extraction. An AVI file carries a video track and an audio track side by side, and converting to FLAC discards the picture and keeps the sound. People do it to turn a lecture, interview, podcast recording or music video into something they can listen to without the video, at a fraction of the file size.

AVI limitations that prompt the switch: Inefficient — much larger than MP4 for the same quality. No browser support. Poor handling of modern codecs and variable frame rate.
What you give up: Much larger than MP3 or AAC. Not supported natively by all portable devices.

Does converting AVI to FLAC reduce quality?

FLAC compresses without discarding data, but it cannot represent everything an AVI file holds. What does not fit is discarded permanently, so converting the result back will not restore it. Keep the AVI original if it is the only copy.

Measured, not estimated

What converting AVI to FLAC actually costs

On every sample measured, the FLAC came out smaller — 1.4× smaller at worst and 4.2× smaller at best.

Each row is one sample chosen to isolate a property these formats treat differently.
Sample	AVI in	FLAC out	Change
An easy clipThe compressible end of the range — a clean tone, or a moving test pattern — where a codec does its best work.	148 KB	106 KB	−29%
A hard clipThe other end — pink noise, or dense video grain. Close to incompressible by design, and the worst case for every codec.	1001 KB	238 KB	−76%

Produced by this site's own converter. The same code that runs in your browser, at the same default settings, so these are the bytes you would download.

Samples are generated from a fixed seed rather than taken from real photographs or documents, so the corpus is reproducible and carries no licensing question — and so the numbers predict the shape of your result rather than its exact size. Measured 2026-10-01. The method, and the command that regenerates every figure on this page, are on the how it works page.

About these formats

Source

Audio Video Interleave

Legacy Microsoft container. Widely readable, inefficient.

Extensions: .avi
MIME type: video/x-msvideo
Best for: Older Windows software · Legacy hardware
Compatibility: Wide but dated. Not supported in browsers.

Target

Free Lossless Audio Codec

Lossless compression — CD quality at roughly half the size.

Extensions: .flac
MIME type: audio/flac
Best for: Hi-fi music libraries · Archiving · Audiophiles
Compatibility: Great on desktop and Android; iOS support is newer.

The soundtrack is decoded and re-encoded. Quality is limited by whatever the video already contained — extracting to FLAC cannot add detail back.

Good to know

AVI to FLAC Converter — questions

How do I convert AVI to FLAC?

Drop your AVI file onto the area above, then press Convert. The FLAC file saves straight to your device. You do not need an account, and there is no watermark.

Is it safe to convert AVI files here — are they uploaded to a server?

No, nothing is uploaded. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website; it is converted there and sent back. That copy is what "upload" means, and it is the part that puts your file out of your control. This site does not do it. Your AVI file is read and converted by the browser you are using right now and never leaves this device, so there is no copy for anyone to store, read or hand over. You can prove it: turn off your Wi-Fi after this page loads and the conversion still works.

Can I convert confidential AVI files, like bank statements or contracts?

Yes, and that is the case this site was built for. Because the file never leaves your device, a confidential document is no more exposed than it is sitting in your own folder — there is no transfer, no copy on someone else's hardware, no retention period to read about and no staff with access. Nothing is logged about the file either: not its name, not its size, not its contents. The one thing worth saying plainly is that this protects the file in transit and at rest on our side, not from anything already on your own computer.

What should I know before converting AVI to FLAC?

The soundtrack is decoded and re-encoded. Quality is limited by whatever the video already contained — extracting to FLAC cannot add detail back.

Does converting to FLAC reduce quality?

Yes, though not through compression — FLAC stores what it holds without discarding data, but it cannot hold everything a AVI file does. What does not fit is dropped permanently, and converting the result back will not bring it back.

How large a file can I convert?

Up to 512 MB per file for this conversion. Because the work happens in your browser, the practical limit is your device's memory — larger files work on a desktop with plenty of RAM and may fail on an older phone.

Can I convert several files at once?

Yes. Add as many as you like and press Convert All. Each file is processed independently, so one failure does not stop the rest, and you can download everything together as a ZIP.

Can I use this on my phone?

Yes. FileTools360 works in mobile browsers on iOS and Android, including choosing files straight from your camera roll. Very large videos may run out of memory on a phone — those are better converted on a laptop.