MyMediaTools

Convert MOV to AVI — Free Online Tool

Convert MOV files to AVI format using H.264 video and MP3 audio encoding, directly in your browser. This conversion is especially useful for making Apple QuickTime footage compatible with legacy Windows software and older media players that predate modern container support.

FFmpeg Command

Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg

Free — no uploads, no signups. Your files never leave your browser.

Estimated output:

Conversion Complete!

Download

How It Works

MOV and AVI both support H.264 video, but this conversion is not a simple remux — the audio must be re-encoded. MOV files typically carry AAC audio, which AVI's ecosystem historically expects as MP3 (libmp3lame). The video stream is re-encoded from the MOV source to H.264 using the libx264 encoder at CRF 23, a perceptually lossless quality level for most content. Because AVI is a rigid legacy container, several MOV features are dropped in the process: chapter markers, embedded subtitles, transparency channels (alpha), and the faststart metadata atom that MOV uses for web streaming are all incompatible with AVI and will not be carried over. The result is a flat, interleaved AVI file with a single H.264 video stream and MP3 audio.

What Each Flag Does

Flag What it does
ffmpeg Invokes the FFmpeg program. When run via this web tool, it executes as FFmpeg.wasm inside your browser using WebAssembly — no data leaves your machine. The same command can be pasted into a terminal with a local FFmpeg installation to process files of any size.
-i input.mov Specifies the input file as a MOV (QuickTime) container. FFmpeg will detect the streams inside — typically H.264 or ProRes video and AAC audio — and use this information to plan the encoding and transcoding steps required for the AVI output.
-c:v libx264 Encodes the output video stream using the libx264 H.264 encoder. Regardless of what video codec the source MOV used (H.264, H.265, ProRes, MJPEG), the output AVI will contain H.264, which is the most practical modern codec for AVI-based compatibility scenarios.
-c:a libmp3lame Transcodes the audio to MP3 using the LAME encoder, replacing whatever audio codec the MOV contained (usually AAC). MP3 is chosen here because it is the most universally supported audio format in AVI players and legacy Windows software, avoiding the poor AAC-in-AVI compatibility seen in older decoders.
-crf 23 Sets the H.264 video quality using the Constant Rate Factor method. A value of 23 is the libx264 default and represents a good balance between file size and perceptual quality for MOV footage converted to AVI. Lower values (e.g., 18) increase quality and file size; higher values (e.g., 28) reduce both.
-b:a 128k Sets the MP3 audio bitrate to 128 kilobits per second in constant bitrate (CBR) mode. CBR is important for AVI specifically because variable bitrate MP3 inside AVI containers is a known cause of audio/video sync drift in many players, making CBR the safer and more compatible choice.
output.avi Defines the output file as an AVI container. FFmpeg infers the AVI format from the .avi extension and structures the encoded H.264 video and MP3 audio into interleaved AVI packets, producing a file compatible with the broad range of legacy Windows applications and devices that AVI conversion is typically intended for.

Common Use Cases

  • Making iPhone or DSLR footage recorded as MOV playable in older Windows video editors like Windows Movie Maker or legacy Sony Vegas versions that have incomplete MOV support
  • Sharing QuickTime recordings with clients or colleagues who use aging enterprise Windows systems where QuickTime is not installed and codec packs expect AVI containers
  • Archiving footage in AVI for use with industrial or scientific software that was built around the AVI/VfW (Video for Windows) framework and never updated to handle MOV
  • Preparing video content for playback on older DVD players, set-top boxes, or media centers that read AVI from USB drives but do not recognize QuickTime containers
  • Converting screen recordings exported from macOS tools like QuickTime Player into AVI so they can be imported into Windows-based e-learning authoring tools with strict format requirements
  • Getting the exact FFmpeg command to batch-convert an entire folder of MOV footage to AVI on a workstation when individual files exceed 1GB

Frequently Asked Questions

Yes, some generation loss occurs because both the video and audio are re-encoded rather than copied. The video is re-encoded with libx264 at CRF 23, which is a visually high-quality setting that most viewers cannot distinguish from the source. The audio is transcoded from AAC (common in MOV) to MP3 at 128k, which is adequate for speech and general content but may introduce slight artifacts in complex music. If your source MOV already used H.264 video, you are going from one lossy encode to another, so keeping the CRF low (e.g., 18) will help preserve quality.
AAC is technically permitted inside an AVI container but is very poorly supported in practice — most AVI-compatible players and legacy software expect either MP3 or PCM audio. Since the primary reason to convert to AVI is broad compatibility with older Windows applications and devices, this tool transcodes the audio to MP3 using the libmp3lame encoder, which is the de facto standard for AVI audio. If you need AAC in an AVI for a specific application, you can modify the FFmpeg command by replacing '-c:a libmp3lame' with '-c:a aac'.
AVI is a 1990s container format with a much simpler structure than MOV, so several features are silently dropped during conversion. Chapter markers, embedded subtitle tracks, and transparency (alpha channel) video — all of which MOV supports — have no equivalent in AVI and will not be preserved. If your MOV file has multiple audio tracks, AVI technically supports multiple streams, but compatibility with that feature varies widely by player. The QuickTime 'faststart' flag used for progressive web streaming is also irrelevant to AVI.
The '-crf 23' flag controls video quality. CRF stands for Constant Rate Factor, and the scale runs from 0 (lossless) to 51 (worst quality). Lower numbers produce better quality at larger file sizes. For high-quality archival conversion of professional MOV footage, try '-crf 18'. For smaller files where quality is less critical, '-crf 28' or '-crf 30' will significantly reduce file size. You can substitute any of these values directly into the displayed FFmpeg command and run it locally on files of any size.
Yes. On macOS or Linux, you can loop over all MOV files in a directory with: for f in *.mov; do ffmpeg -i "$f" -c:v libx264 -c:a libmp3lame -crf 23 -b:a 128k "${f%.mov}.avi"; done. On Windows Command Prompt, use: for %f in (*.mov) do ffmpeg -i "%f" -c:v libx264 -c:a libmp3lame -crf 23 -b:a 128k "%~nf.avi". This is particularly useful when you have many large MOV files that exceed the 1GB browser limit of this tool.
It depends on what codec your source MOV used. If the MOV contained H.264 video at a similar bitrate, the AVI output will be roughly comparable in size, with a slight reduction from switching to MP3 audio. If the MOV contained a high-bitrate ProRes or MJPEG video track (common from professional cameras), the AVI output will be dramatically smaller because H.264 at CRF 23 is far more efficient. Conversely, a low-bitrate MOV re-encoded at CRF 23 may produce a larger AVI if the encoder targets quality rather than matching the original file size.

Technical Notes

AVI uses the legacy OpenDML extension for files over 2GB, but compatibility with this extension varies by application — some older software cannot open oversized AVI files even if the codec is correct. The libx264 encoder used here defaults to the 'high' profile with automatic level detection, which is widely compatible but may still exceed what very old AVI decoders expect; if targeting truly ancient hardware, adding '-profile:v baseline -level 3.0' to the command improves compatibility at some cost to compression efficiency. On the audio side, MP3 inside AVI has a known limitation with variable bitrate (VBR) encoding causing audio sync drift in some players — the '-b:a 128k' flag enforces constant bitrate (CBR) output from libmp3lame, which avoids this classic AVI audio sync problem. Metadata such as creation date, camera model, and GPS coordinates embedded in the MOV file will not be transferred to the AVI output, as AVI has no standardized metadata specification beyond basic riff chunk headers. If your MOV source has an alpha (transparency) channel encoded with PNG or a ProRes 4444 codec, that transparency data will be discarded entirely, and the resulting AVI will have an opaque background.

Related Tools

Convert MOV to MKV Convert MOV to MOD Convert MOV to 3GP Convert M4V to AVI Convert RM to AVI Convert MXF to AVI Compress MOV Extract Audio MOV to MP3