AV1 to FLAC Converter

Convert AV1 to FLAC: Read This First

A bare .av1 file is a raw AV1 video bitstream — by design it carries picture only, with no audio track inside it. So if your goal is to pull a soundtrack out of an .av1 and save it as lossless FLAC, there is usually nothing to pull: the resulting file would be silent. This page is honest about why, shows how the converter behaves, and points you to the file that actually holds your audio.

Why a Raw AV1 File Has No Sound

AV1 is the video codec from the Alliance for Open Media, whose bitstream specification was released in 2018. That specification describes a video codec built from Open Bitstream Units (OBUs) — it defines nothing about audio. A file saved with a plain .av1 (or .obu, or .ivf) extension is normally a raw elementary stream: a sequence of coded AV1 video frames and nothing else. There is no container around it to hold a parallel audio track, so there is no sound to decode.

The AV1 video you watched with sound almost certainly lived inside a container — a .webm, .mkv, or .mp4 — that wrapped the AV1 video next to a separate audio track (usually Opus, sometimes AAC). When a file is exported or demuxed down to a bare .av1, that audio is left behind. If you ran this conversion and got a silent FLAC, that is not a bug in the converter — it is the raw AV1 stream doing exactly what the format specifies.

Note: .av1 here means an AV1 video bitstream. It is not the same as AVIF, which is a still-image format that also uses AV1 frames. This page is about the video stream.

How to Convert AV1 to FLAC

1. Upload Your AV1 File: Drag and drop your .av1 onto the page, or click "+ Add Files" to choose it from your computer. You can queue several files to process with the same settings.
2. Set the Compression Level: Open "Show All Options" and use the Compression level slider. FLAC is lossless at every setting — the level only trades encode speed against file size. A lower number encodes faster but leaves the file larger; a higher number squeezes the smallest file. The audio itself is bit-for-bit identical either way.
3. Set Audio Channel and Sample Rate (Optional): Audio Channel and Audio Sample Rate both default to Original, which copies the decoded audio untouched — the safest choice. Force a fixed rate such as 44100 Hz or 48000 Hz only if a target device needs it, and use Trim to grab just a portion of the timeline.
4. Convert and Download: Click "Convert" and download your FLAC. No sign-up, no watermark.

Walk-through: Will Your AV1 File Actually Have Sound?

Whether you get audio depends entirely on what you actually uploaded, because the AV1 specification defines only video — any audio rides in the container alongside it. The common cases:

• A true raw .av1 elementary stream: This is video only. The same is true for .obu and .ivf dumps, which by design hold a single elementary video stream. A FLAC made from any of these will be empty or silent — there is nothing inside to extract. Nothing in the settings can create a soundtrack that was never in the file.
• A container that was misnamed .av1: Occasionally a .webm or .mkv gets renamed with an .av1 extension. If your file is secretly a container with a real audio track, the converter will decode that track to FLAC normally. But that is the exception, not the rule.
• You actually want the soundtrack of an AV1 video: then you are starting from the wrong file. Upload the full container — the .webm, .mkv, or .mp4 that holds both the AV1 video and the audio — to the matching tool below.

If you are not sure whether your file is a bare stream or a container, check the extension: .av1, .obu, and .ivf are video-only elementary streams, while .webm, .mkv, and .mp4 can carry both video and audio together.

Where Your Audio Probably Is

• The original download or recording: the playable file you started from is almost always a .webm, .mkv, or .mp4. That container holds the audio. Convert that file, not the demuxed .av1.
• An MP4 container: use MP4 to FLAC to decode the audio track from an MP4 (which can carry AV1 video) into lossless FLAC.
• An MKV container: use MKV to FLAC for Matroska files, which frequently pair AV1 video with Opus, AC-3, or FLAC audio.

When This Doesn't Work

If your AV1 file is a true elementary stream with no companion audio, no tool can manufacture sound that was never encoded — the fix is to find the original container or the separate audio file. And keep one thing in mind even when audio is present: video containers normally store audio as a lossy codec such as Opus or AAC, so packaging it into FLAC gives you a lossless wrapper around already-lossy audio. FLAC will preserve exactly what is there, but it cannot restore detail the original lossy encode discarded — it is not a quality upgrade. If you only want the video in a playable package rather than its audio, transcode the bare stream with AV1 to WebM to make it playable, or use AV1 to MP4 for a broadly compatible container.

Frequently Asked Questions

Why is my AV1 to FLAC output silent or empty?

Because a raw .av1 file is an AV1 video elementary stream and holds no audio. There is no soundtrack inside the file to decode, so any FLAC produced from a bare .av1 will be silent. The audio for that footage lived in the container (a .webm, .mkv, or .mp4) the video was demuxed from. Convert that container to FLAC instead.

Does an .av1 file contain audio I can extract?

Normally no. AV1, the video codec from the Alliance for Open Media, defines only video, and a plain .av1, .obu, or .ivf file is a raw video bitstream with no audio track. You only get sound out if the file you uploaded is actually a container (such as a WebM misnamed .av1) that happens to carry an audio track alongside the video.

Is an .av1 file the same as an AVIF image?

No. AVIF is a still-image (and image-sequence) format that stores AV1-coded frames inside an ISO base media container, whereas a bare .av1 is a raw AV1 video elementary stream. They share the AV1 frame coding but are different file types — this converter expects the video bitstream, not an AVIF image.

Will FLAC improve the quality of audio extracted from a video?

No. FLAC is the Free Lossless Audio Codec, so it stores whatever it is given without further loss — but the audio inside an AV1 container was almost always encoded with a lossy codec like Opus or AAC. Converting that to FLAC produces a lossless file that faithfully preserves the lossy source; it cannot recover detail the original encode already threw away. FLAC here means a clean, edit-ready copy, not a higher-fidelity one.

How do I get FLAC audio from a video that actually has sound?

Start from a file that genuinely contains an audio track. If your video is an MP4, use MP4 to FLAC; if it is a Matroska file, use MKV to FLAC. Both formats interleave video and audio, so the converter has a real audio track to decode into FLAC. A bare .av1 stream does not.

What does the Compression level slider do for FLAC?

FLAC is lossless at every compression level, so the slider only changes how hard the encoder works to shrink the file — not the audio quality. In our testing, a higher level produces a smaller FLAC and a slower encode, while a lower number finishes faster but leaves a slightly larger file. The decoded samples are bit-for-bit identical regardless of where you set it.

Is this AV1 converter free and private?

Yes. There is no sign-up and no watermark. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after conversion — never shared or made public.