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Convert AVI to MP4 Online Free

Upload your AVI video, choose MP4 as the output format, and convert directly in your browser with no signup or installation required. Enjoy fast, secure, watermark-free video conversion that works on any device and is perfect for everyday files.

For more powerful AVI to MP4 conversion needs, UniConverter Desktop gives you much more:

  • Convert AVI to MP4 in batch and save time on large files
  • Enjoy up to 130× faster conversion speed
  • Support for 1,000+ audio/video/image formats
  • An all-in-one toolkit including editing, enhancement, and more
Batch Convert AVI to MP4
Batch Convert AVI to MP4
Batch Convert AVI to MP4

How to Convert AVI to MP4 Online

upload mkv format file
Step 1

Upload your AVI video file

Click the upload area or drag and drop your AVI file from your computer, phone, or cloud storage into the converter. Our tool automatically detects the source format, so you do not need any technical setup before starting the video conversion.

choose mp4 as output format
Step 2

Choose MP4 as the output format

Select MP4 as the target format from the list of video options to ensure the converted file plays smoothly on phones, tablets, browsers, and social platforms. The online converter uses a balanced preset, avoiding complicated parameter settings for you.

download converted mp4 video
Step 3

Start conversion and download your MP4

Hit the Convert button to start processing your AVI file on our secure servers. When the progress finishes, download the MP4 video to your device or save it to your preferred cloud service, ready for playback, editing, or sharing anywhere you need.

AVI vs MP4: Why Change the Video Format

AVI
MP4
File Extension .avi .mp4
Full Name Audio Video Interleave MPEG-4 Part 14
Description AVI is a container format introduced by Microsoft that can hold video and audio using various codecs. It is known for flexibility and relatively large file sizes, and is often used for older recordings, camcorder footage, and archival material. MP4 is a modern, highly compatible container format widely used for streaming, mobile playback, and online platforms. It offers good compression with popular codecs like H.264 and H.265, balancing video quality and file size for everyday sharing.
Associated Programs Windows Media Player, VLC media player, KMPlayer, PotPlayer, VirtualDub VLC media player, QuickTime Player, Windows Movies & TV, iTunes, many mobile video apps
Initial Release 1992 2001
Developer Microsoft Moving Picture Experts Group (MPEG)
Common Use Cases Legacy camera recordings, older PC video files, raw or lightly compressed footage, offline backups that prioritize compatibility with classic Windows software. Online streaming, social media uploads, mobile and tablet playback, cloud storage, video editing workflows that require broad device support.
MIME Type video/x-msvideo video/mp4

Key Features of Our AVI to MP4 Converter

One-click online AVI to MP4 conversion

Use the browser-based converter to change AVI into MP4 with just an upload and a single click, no software installation or account needed. Ideal for quick, single-file tasks when you simply need a compatible MP4 video that works everywhere.

Secure online processing with temporary storage

Files are transferred over secure connections and stored only for the time required to process your conversion. After the job completes, videos are removed according to our retention policy, keeping your personal recordings and client projects private.

Mobile and cloud-ready MP4 output

Create MP4 files that work smoothly on iPhone, Android, tablets, laptops, and popular cloud services. After converting, you can upload the video to platforms like Google Drive or social networks without extra re-encoding or compatibility issues.

High-quality desktop conversion with format control

Install the desktop software to fine-tune encoding settings such as codec, resolution, frame rate, and bitrate. This lets you prioritize image quality, file size, or speed, and achieve more consistent results than basic online presets for demanding projects.

Desktop batch conversion from AVI to MP4

Use the desktop application to queue and convert multiple AVI videos to MP4 in one go, saving time on large libraries. You can apply shared output settings across all files, ideal for series, event shoots, or long-term archives that need updating.

Advanced desktop export parameters and presets

On desktop, adjust export parameters in detail or choose device-specific presets tailored for phones, tablets, and streaming platforms. You can tweak audio tracks, subtitles, and compression options, and then reuse these custom profiles on future projects.

Batch Convert Now
Convert Online
Batch Convert Now
Convert Online
Batch Convert Now
Convert Online

AVI to MP4 Conversion FAQs

Upload the AVI video to the online converter, select MP4 as the target format, and start the process in your browser. The service runs on our servers, so you do not need to install anything. When it is done, download the finished file or save it to cloud storage.
Changing formats often involves re-encoding, which can slightly impact clarity if heavy compression is used. Our online tool uses balanced settings for everyday use, while the desktop app lets you control bitrate and codec so you can better preserve detail and audio fidelity.
The best option depends on your needs. For quick, occasional tasks, the browser-based tool is simple and free. If you handle large projects, want batch conversion, or need to fine-tune export settings, the desktop software offers more power and stable performance on both platforms.
Google Drive can store AVI videos and preview some clips in the browser, but it does not provide a full conversion feature to change them into another format. To get a compatible MP4 file, use our web converter or desktop program, then upload the processed result to your Drive account.
For very big or long videos, use the desktop application, which allows you to choose efficient codecs and higher bitrates. This helps keep visual detail while still reducing file size. You can also enable hardware acceleration to speed up processing on capable graphics cards.

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— TG

“I have been using Wondershare UniConverter for many years. It has been one of the best ways to download, screen capture and convert videos. It has been my go to for video download and conversion.”

— Alan Horner

What Users Say About Our AVI to MP4 Tool

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Start Converting AVI to MP4 Today

Upload a video to convert AVI to MP4 online in a few clicks, or download the desktop app for batch jobs and finer control. Enjoy secure processing, no watermarks, and high-quality output ready for any device or platform.
Batch Process Now Upload AVI File
Batch Process Now Upload AVI File
Batch Process Now Upload AVI File
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