How to Convert MP4/MPEG-4/H.264 to AVI on Desktop and Online?

MP4 and AVI are both video container formats, but they are often used in different situations. MP4 is widely used on modern phones, websites, and media players, while AVI may still be required by some older TVs, DVD players, car media systems, editing programs, or legacy devices. If your device only accepts AVI, you can convert MP4 to AVI with a desktop program or an online tool.

Also, note that MP4, MPEG-4, and H.264 are not interchangeable terms. MP4 usually refers to a .mp4 container. MPEG-4 is a family of compression standards, while H.264/AVC is the MPEG-4 Part 10 video codec. H.264 video is commonly stored in MP4, MOV, MKV, MTS/M2TS, and other containers, and some cameras or CCTV systems may save a raw .h264/.264 video stream. The desktop methods below can handle these common cases and convert the video to AVI.

One more thing matters: AVI is also a container, not a codec. An AVI file can contain H.264, DivX, Xvid, and other video streams. If you only need a different container and your target player accepts H.264 inside AVI, keeping H.264 can avoid an unnecessary generation of quality loss. If an older device specifically expects DivX or Xvid AVI, however, the video needs to be re-encoded to that codec.

• Use WonderFox Free HD Video Converter Factory

As a free MP4 to AVI converter for Windows, WonderFox Free HD Video Converter Factory lets you convert MP4 videos to AVI and many other common formats without watermarks. It also accepts many MPEG-4 and H.264/AVC sources, including videos stored in MOV, M4V, MTS, M2TS, and other common containers. The same basic workflow therefore works for most MP4, MPEG-4, and H.264 to AVI conversions.

This method is better than online tools when your video is large, private, or slow to upload. You can also adjust resolution, bitrate, frame rate, aspect ratio, and volume before conversion. If your old device is picky about AVI playback, try using a more compatible video codec such as Xvid or DivX and a common audio codec such as MP3 when available. For a modern player that accepts H.264 in AVI, you can instead keep H.264 when the encoder option is available.

DownloadDownload and install this free converter and start your conversion with ease.

------ Try HD Video Converter Factory Pro for Batch MP4/MPEG-4/H.264 to AVI Conversion

Free HD Video Converter Factory has an upgraded version called WonderFox HD Video Converter Factory Pro. It is a better choice if you want to convert multiple MP4, MPEG-4, or H.264 files to AVI simultaneously, convert large files faster, or keep more control over output quality. It supports hardware acceleration, batch conversion, and 500+ output presets.

Video conversion usually involves re-encoding, so “no quality loss” is not always guaranteed. But with suitable settings, such as keeping the original resolution and frame rate and choosing a proper bitrate, you can reduce visible quality loss while making the AVI file more compatible with your target device. The workflow is the same as using the free version, except that you can import a folder or multiple videos for batch conversion and enable acceleration when available.

For H.264 sources, there are two useful choices. If the target device accepts H.264 video inside AVI, select AVI and keep H.264 as the video encoder. In supported H.264-to-H.264 container changes, the Pro version can trigger Lightning Mode when the output parameters remain compatible, so the video stream does not have to be fully re-encoded. This is faster and avoids generational video quality loss. If the destination is an older TV, DVD player, car system, or other device that only accepts DivX/Xvid AVI, choose the required codec instead; that route re-encodes the video and may increase the file size or slightly reduce quality.

In addition to converting MP4, MPEG-4, and H.264 videos to AVI, the Pro version also includes a video downloader, screen recorder, simple editor, GIF maker, and toolbox for everyday multimedia tasks.

• Use HandBrake 0.9.3 (Legacy)

HandBrake can also be used to convert MP4 to AVI, but only with its old legacy builds. HandBrake 0.9.3 is the last version that supports AVI output. Later and current HandBrake versions no longer export AVI, so do not install the latest HandBrake if your only purpose is to create an AVI file.

Compared with the first software, HandBrake has a little learning curve. Also, since version 0.9.3 is outdated and no longer supported, it is better suited for users who already have the legacy installer and only need to process non-sensitive files. If you want a maintained converter, use the WonderFox method above.

Here is how to change MP4 to AVI with HandBrake 0.9.3:

Step 1: Launch HandBrake 0.9.3.

Step 2: Click “Source” in the upper left corner. Choose the MP4 file you want to convert and add it to the software.

Step 3: Click the “Browse” button under “Destination” to set an output path for the converted file.

Step 4: Choose AVI as the target format in the “Output Settings” section.

Step 5: Press the green Start button to begin converting MP4 to AVI format.

For multiple MP4 video conversions, use WonderFox HD Video Converter Factory Pro instead. Later HandBrake versions added more queue/batch features, but they no longer provide AVI output.

• Use CloudConvert.com

Many online converters can turn MP4 into AVI without installing software. This is convenient when you only have one small, non-private file to convert. An MP4 file that happens to use H.264 video can normally be uploaded the same way, but support for raw .h264/.264 streams varies by website. For raw H.264 or files from CCTV systems, the desktop method is usually more dependable. Here, I will take CloudConvert.com as an example to show the general MP4 workflow.

CloudConvert lets you upload a file from your computer, cloud storage, or a URL, and it also provides optional settings such as codec, resolution, and trimming. File size, daily conversion time, and advanced options may vary depending on the current free plan and your account status, so check the website before uploading a large video.

Step 1: Visit https://cloudconvert.com/mp4-to-avi.

Step 2: Click “Select File” to add your MP4 file.

Step 3: Make sure the output format is AVI. Open the settings panel if you need to adjust codec, resolution, or other parameters.

Step 4: Press “Convert” to start uploading and converting the video. Then download the converted file when it is finished.

Note: Online video conversion may take a long time, especially for large files or slow networks. Do not upload private, sensitive, or copyrighted videos to a third-party website unless you trust the service and understand its terms.

• Other Online MP4 to AVI Converters

If CloudConvert is not available or does not meet your needs, you can also try other browser-based converters, such as Super-Converter, 123APPS Video Converter, Converter App, or Video-Converter-Online.

These web tools may offer different limits, upload methods, and settings. Some claim no watermark, no sign-up, or no conversion-time limit, but the actual experience can still be affected by browser limits, server load, upload speed, and file size. For a short clip, online conversion is quick enough. For a long movie, batch task, or confidential file, desktop software is usually more reliable.

1. Can I convert MP4 or H.264 to AVI without losing quality?

Not always. If the video has to be re-encoded, some quality loss is possible. To keep the result close to the original, keep the source resolution and frame rate, choose a suitable bitrate, and avoid repeated conversions. For a compatible H.264 source and H.264-in-AVI output, a remux-like container change can avoid re-encoding the video stream.

2. Is MP4 the same as MPEG-4 or H.264?

No. MP4 is a container format with the .mp4 extension. MPEG-4 is a family of coding standards. H.264/AVC is MPEG-4 Part 10 and is a video codec, not a container. H.264 video is often stored inside MP4, but it can also be carried by AVI, MOV, MKV, MTS/M2TS, and other containers.

3. Is there a free tool to convert MP4 to AVI?

Yes. WonderFox Free HD Video Converter Factory can convert MP4 to AVI on Windows for free. Online converters can also do this for small files. HandBrake 0.9.3 legacy can also export AVI, but it is outdated and no longer supported. Current HandBrake versions do not export AVI.

4. Can I convert multiple MP4 or H.264 files to AVI at once?

Yes. WonderFox HD Video Converter Factory Pro provides batch conversion, so you can add multiple MP4, MPEG-4, or H.264 files, choose AVI once, and convert them together.

5. Why won’t my converted AVI play on my old device?

AVI is only a container. Your device also needs to support the video and audio codecs inside the AVI file. If playback fails, try a more compatible codec combination, lower the resolution or bitrate, or check your device manual for the supported AVI specifications.

6. How can I convert MP4 to AVI online?

You can use an online converter like CloudConvert. Upload the MP4 file, select AVI as the output format, adjust optional settings if needed, start the conversion, and download the converted file. For privacy and speed, desktop software is better for large or sensitive videos.

7. Can AVI contain H.264 video?

Yes. AVI is a container and can carry H.264 video. However, some older devices that advertise “AVI support” actually expect DivX or Xvid video inside the AVI file. If an H.264 AVI does not play, check the device specifications and convert the video codec to the required format rather than changing only the file extension or container.

Converting MP4, MPEG-4, or H.264 video to AVI is not difficult, but the best method depends on both the source codec and the target device. For H.264 sources, keep H.264 inside AVI when your player supports it and you want to avoid unnecessary re-encoding; switch to DivX or Xvid when a legacy device requires one of those AVI codecs. For a large video, a batch task, a raw H.264 stream, or a private file, WonderFox Free HD Video Converter Factory or its Pro version is the more stable choice on Windows. For a small non-sensitive MP4 clip, CloudConvert and similar online tools are convenient. HandBrake 0.9.3 can still be used for AVI output if you already have the legacy version, but current HandBrake releases are not suitable for AVI conversion.